{"gene":"FAM161A","run_date":"2026-06-09T23:54:43","timeline":{"discoveries":[{"year":2012,"finding":"FAM161A localizes to the base of the photoreceptor connecting cilium in human, mouse and rat, and to the ciliary basal body in ciliated mammalian cells. siRNA-mediated depletion of FAM161A in cultured cells causes reduction in assembled primary cilia, establishing a functional role in ciliogenesis.","method":"Immunofluorescence, immunohistochemistry, siRNA knockdown with ciliary assembly readout","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal localization experiments across multiple species, siRNA knockdown with defined cellular phenotype, replicated by independent lab (PMID:22791751)","pmids":["22940612","22791751"],"is_preprint":false},{"year":2012,"finding":"FAM161A directly binds microtubules; overexpressed FAM161A associates with microtubules during interphase and mitosis and increases microtubule acetylation and stabilization. The evolutionarily conserved C-terminal UPF0564 domain mediates microtubule binding.","method":"Overexpression in cultured cells, immunofluorescence for microtubule co-localization, tubulin acetylation assay, domain deletion analysis","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single lab, overexpression system, multiple readouts (co-localization, acetylation, domain mapping) but no in vitro reconstitution with purified protein","pmids":["22791751"],"is_preprint":false},{"year":2012,"finding":"The UPF0564 domain of FAM161A mediates homo- and heterotypic interaction with FAM161B, as well as binding to ciliopathy-associated proteins lebercilin, CEP290, OFD1, and SDCCAG8, as demonstrated by yeast two-hybrid and pull-down experiments in cultured cells and bovine retinal extracts.","method":"Yeast two-hybrid, pull-down assays in cultured cells and bovine retinal extracts","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — interactions validated by orthogonal methods (Y2H + pull-down) in two independent labs using native tissue (bovine retina) and cultured cells","pmids":["22940612","22791751"],"is_preprint":false},{"year":2014,"finding":"In Fam161a gene-trap mice lacking the C-terminal domain, the connecting cilium is significantly shortened, ciliary microtubule doublets are spread, and outer segment disk organization is disturbed. Interactors lebercilin and Cep290 are mislocalized to the basal body/proximal connecting cilium, and outer segment cargo proteins opsin and rds/peripherin 2 are misrouted, indicating the C-terminal domain is required for molecular delivery into the outer segment cilium.","method":"Gene-trap mouse model, electron microscopy, immunohistochemistry, western blot, ERG","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo genetic loss-of-function with multiple orthogonal structural and functional readouts (EM, IHC, ERG), defined pathway placement of cargo misrouting","pmids":["24833722"],"is_preprint":false},{"year":2015,"finding":"Yeast two-hybrid screening of human and bovine retinal cDNA libraries using FAM161A fragments as bait identified 53 interactors enriched in ciliary, Golgi apparatus, centrosomal, and microtubule network proteins, including AKAP9, FIP3, GOLGA3, KIFC3, KLC2, PDE4DIP, NIN, and TRIP11. Key interactions were validated by co-immunoprecipitation and proximity ligation assay, placing FAM161A as a member of the Golgi-centrosomal interactome.","method":"Yeast two-hybrid (cDNA library screen), co-immunoprecipitation, proximity ligation assay","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 / Moderate — Y2H screen validated by orthogonal methods (Co-IP + PLA) in a single lab with native retinal tissue used as library source","pmids":["25749990"],"is_preprint":false},{"year":2015,"finding":"FAM161A localization follows the centrosome during all stages of mitosis, suggesting compartmentalization related to centrosomal function during cell cycle progression as well as ciliary basal body function in G0.","method":"Cell cycle staging with immunofluorescence localization of FAM161A relative to centrosomal markers","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 3 / Weak — single lab, single method (immunofluorescence), no functional perturbation to test consequence of centrosomal localization","pmids":["25749990"],"is_preprint":false},{"year":2015,"finding":"Mutant FAM161A transcripts harboring nonsense mutations are actively degraded by nonsense-mediated mRNA decay (NMD) in patient-derived lymphoblasts, indicating that the disease mechanism involves FAM161A protein deficiency rather than production of a truncated protein.","method":"Analysis of FAM161A mRNA levels in cultured lymphoblasts from patients with nonsense mutations","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 3 / Weak — single lab, single molecular method in patient-derived cells, no NMD inhibitor control reported in abstract","pmids":["24651477"],"is_preprint":false},{"year":2020,"finding":"Structural bioinformatics analysis predicts FAM161A is a homologue of the microtubule nucleation factor TPX2, with three copies of the extended loop element and one short helix homologous to the TPX2 microtubule-nucleating elements, suggesting FAM161A binds microtubules in the same way as TPX2.","method":"Computational profile-profile homology search (PSI-BLAST, HHblits, HHpred), multiple sequence alignment","journal":"F1000Research","confidence":"Low","confidence_rationale":"Tier 4 / Weak — purely computational prediction, no experimental validation reported","pmids":["33093951"],"is_preprint":false},{"year":2022,"finding":"C8orf37 physically interacts with FAM161A; the N-terminal region of C8orf37 binds to residues 341–517 within the UPF0564 domain of FAM161A. Both proteins co-localize at the ciliary base of photoreceptors in marmoset retina.","method":"Yeast two-hybrid screen, co-immunofluorescence, proximity ligation assay (PLA) in marmoset retinal sections and HEK293 cells, interaction domain mapping","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Y2H validated by PLA and co-localization in native tissue (marmoset retina), domain mapping performed; single lab","pmids":["36233334"],"is_preprint":false},{"year":2012,"finding":"FAM161A expression in the retina is transcriptionally regulated by the photoreceptor transcription factor CRX, as demonstrated by chromatin immunoprecipitation showing CRX binding to the Fam161a promoter and organotypic reporter assays in explanted retinas.","method":"Chromatin immunoprecipitation (ChIP), organotypic retinal explant reporter assays","journal":"American journal of human genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — two orthogonal methods (ChIP + reporter assay) in a single study establishing FAM161A as a CRX transcriptional target","pmids":["20705278"],"is_preprint":false},{"year":2024,"finding":"In Fam161a-deficient mice, gene augmentation using AAV vectors expressing both the long (exon 4-containing) and short isoforms of human FAM161A under a weak promoter (FCBR1-F0.4) restored FAM161A localization to the connecting cilium and improved retinal function, whereas strong-promoter vectors or single-isoform delivery did not enhance retinal function despite improving cell survival, establishing that precise dosing and delivery of both isoforms is required for functional rescue.","method":"Subretinal AAV injection in Fam161a KO mice, ERG, OCT, immunohistochemistry, comparison of multiple vector/promoter/isoform combinations","journal":"EMBO molecular medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo rescue experiment with multiple vector comparisons and functional readout (ERG), single lab but rigorous multi-condition design","pmids":["38504136"],"is_preprint":false}],"current_model":"FAM161A is a centrosomal-ciliary microtubule-associated protein that localizes to the photoreceptor connecting cilium and basal body, where its C-terminal UPF0564 domain mediates direct microtubule binding (promoting acetylation and stabilization), homo/heterotypic interactions with FAM161B, and binding to ciliopathy proteins (lebercilin, CEP290, OFD1, SDCCAG8, C8orf37); it is also a member of the Golgi-centrosomal interactome; loss of its C-terminal domain in vivo disrupts connecting cilium architecture, mislocalizes ciliary proteins, causes misrouting of outer segment cargo (opsin, peripherin-2), and leads to progressive photoreceptor degeneration, while its retinal expression is transcriptionally controlled by CRX."},"narrative":{"mechanistic_narrative":"FAM161A is a centrosomal and ciliary microtubule-associated protein that organizes the photoreceptor connecting cilium and basal body to support outer segment biogenesis and protein delivery [PMID:22940612, PMID:22791751, PMID:24833722]. Through its evolutionarily conserved C-terminal UPF0564 domain it binds microtubules directly, promoting their acetylation and stabilization, and engages a network of ciliopathy-associated proteins including FAM161B, lebercilin, CEP290, OFD1, SDCCAG8, and C8orf37 [PMID:22791751, PMID:22940612, PMID:36233334]. Beyond its ciliary role, FAM161A is a member of the Golgi-centrosomal interactome and tracks with the centrosome throughout mitosis, interacting with centrosomal and microtubule-network proteins such as AKAP9, NIN, PDE4DIP, KIFC3, and TRIP11 [PMID:25749990]. In vivo loss of the C-terminal domain shortens the connecting cilium, splays ciliary microtubule doublets, mislocalizes lebercilin and Cep290, and misroutes outer segment cargo (opsin and peripherin-2), establishing this domain as essential for molecular delivery into the outer segment [PMID:24833722]. Its retinal expression is transcriptionally driven by the photoreceptor factor CRX [PMID:20705278], and disease-associated nonsense alleles are eliminated by nonsense-mediated decay, indicating that pathology arises from protein deficiency [PMID:24651477]; gene augmentation restoring both FAM161A isoforms at controlled dosage rescues connecting-cilium localization and retinal function in deficient mice [PMID:38504136].","teleology":[{"year":2012,"claim":"Establishing where FAM161A acts and whether it is functionally required for cilia answered the first question of its cellular role.","evidence":"Immunofluorescence/immunohistochemistry across human, mouse and rat plus siRNA knockdown with a ciliary assembly readout in cultured cells","pmids":["22940612","22791751"],"confidence":"High","gaps":["Does not define the molecular activity underlying ciliogenesis defect","Connecting-cilium versus basal-body specific functions not separated"]},{"year":2012,"claim":"Identifying direct microtubule binding via the UPF0564 domain provided a candidate biochemical mechanism for FAM161A's ciliary structural role.","evidence":"Overexpression in cultured cells with microtubule co-localization, tubulin acetylation assays, and domain-deletion mapping","pmids":["22791751"],"confidence":"Medium","gaps":["No in vitro reconstitution with purified protein","Acetylation/stabilization shown in overexpression, not endogenous setting"]},{"year":2012,"claim":"Mapping UPF0564-mediated interactions placed FAM161A within a ciliopathy protein network at the connecting cilium.","evidence":"Yeast two-hybrid and pull-down assays in cultured cells and bovine retinal extracts","pmids":["22940612","22791751"],"confidence":"High","gaps":["Hierarchy and stoichiometry of the interaction network not resolved","Functional consequence of each interaction not tested"]},{"year":2012,"claim":"Demonstrating CRX control of FAM161A transcription connected its expression to the photoreceptor gene regulatory program.","evidence":"Chromatin immunoprecipitation and organotypic retinal explant reporter assays","pmids":["20705278"],"confidence":"Medium","gaps":["Other regulators of FAM161A not addressed","Isoform-specific transcriptional control not examined"]},{"year":2014,"claim":"In vivo deletion of the C-terminal domain established that FAM161A is required for connecting-cilium architecture and for routing cargo into the outer segment.","evidence":"Gene-trap mouse model analyzed by electron microscopy, immunohistochemistry, western blot, and ERG","pmids":["24833722"],"confidence":"High","gaps":["Mechanism by which cargo (opsin, peripherin-2) is sorted not defined","Distinguishes C-terminal requirement but not roles of other regions"]},{"year":2015,"claim":"A retinal interactome screen extended FAM161A beyond the cilium into a Golgi-centrosomal network.","evidence":"Yeast two-hybrid cDNA library screen validated by co-immunoprecipitation and proximity ligation assay","pmids":["25749990"],"confidence":"High","gaps":["Functional significance of Golgi-centrosomal partners untested","Validated only a subset of 53 candidate interactors"]},{"year":2015,"claim":"Tracking FAM161A with the centrosome through mitosis raised the possibility of a cell-cycle role distinct from its G0 ciliary function.","evidence":"Cell-cycle staged immunofluorescence relative to centrosomal markers","pmids":["25749990"],"confidence":"Medium","gaps":["No functional perturbation to test mitotic consequence","Single method without orthogonal validation"]},{"year":2015,"claim":"Showing NMD degradation of nonsense alleles clarified that disease results from protein loss rather than a dominant truncated product.","evidence":"FAM161A mRNA level analysis in patient-derived lymphoblasts","pmids":["24651477"],"confidence":"Medium","gaps":["No NMD-inhibitor control reported","Limited to nonsense mutations, not other allele classes"]},{"year":2020,"claim":"A structural-homology prediction proposed that FAM161A binds microtubules in a TPX2-like manner, offering a mechanistic hypothesis for its tubulin interaction.","evidence":"Computational profile-profile homology search and multiple sequence alignment","pmids":["33093951"],"confidence":"Low","gaps":["Purely computational with no experimental validation","Predicted nucleation activity not tested biochemically"]},{"year":2022,"claim":"Identifying C8orf37 as a UPF0564-domain partner co-localized at the ciliary base extended FAM161A's ciliopathy interaction map.","evidence":"Yeast two-hybrid, co-immunofluorescence, PLA in marmoset retina and HEK293 cells, with interaction domain mapping","pmids":["36233334"],"confidence":"Medium","gaps":["Functional consequence of the C8orf37 interaction not established","Single lab without reciprocal in vivo validation"]},{"year":2024,"claim":"Gene-augmentation rescue defined that restoring both FAM161A isoforms at controlled dosage is necessary for functional recovery, addressing therapeutic requirements.","evidence":"Subretinal AAV delivery in Fam161a KO mice with ERG, OCT, IHC across multiple vector/promoter/isoform combinations","pmids":["38504136"],"confidence":"Medium","gaps":["Distinct functional roles of long versus short isoforms not mechanistically resolved","Single-lab demonstration in mouse only"]},{"year":null,"claim":"The biochemical mechanism by which FAM161A engages microtubules and directs outer-segment cargo trafficking remains undefined.","evidence":"","pmids":[],"confidence":"Low","gaps":["No reconstituted in vitro microtubule-binding/nucleation assay with purified FAM161A","Mechanism linking the interaction network to cargo sorting not established","Isoform-specific molecular functions unresolved"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[1,2]}],"localization":[{"term_id":"GO:0005929","term_label":"cilium","supporting_discovery_ids":[0,3]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[0,4,5]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[1,4]},{"term_id":"GO:0005794","term_label":"Golgi apparatus","supporting_discovery_ids":[4]}],"pathway":[{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[0,3]},{"term_id":"R-HSA-9709957","term_label":"Sensory Perception","supporting_discovery_ids":[3,10]}],"complexes":[],"partners":["FAM161B","LCA5","CEP290","OFD1","SDCCAG8","C8ORF37","AKAP9","NIN"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q3B820","full_name":"Protein FAM161A","aliases":[],"length_aa":660,"mass_kda":76.8,"function":"Involved in ciliogenesis","subcellular_location":"Cytoplasm, cytoskeleton, cilium basal body; Cell projection, cilium; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome, centriole","url":"https://www.uniprot.org/uniprotkb/Q3B820/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/FAM161A","classification":"Not Classified","n_dependent_lines":5,"n_total_lines":1208,"dependency_fraction":0.0041390728476821195},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/FAM161A","total_profiled":1310},"omim":[{"mim_id":"614784","title":"POC1 CENTRIOLAR PROTEIN B; POC1B","url":"https://www.omim.org/entry/614784"},{"mim_id":"613596","title":"FAMILY WITH SEQUENCE SIMILARITY 161, MEMBER A; FAM161A","url":"https://www.omim.org/entry/613596"},{"mim_id":"606068","title":"RETINITIS PIGMENTOSA 28; RP28","url":"https://www.omim.org/entry/606068"},{"mim_id":"268000","title":"RETINITIS PIGMENTOSA; RP","url":"https://www.omim.org/entry/268000"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Centrosome","reliability":"Supported"},{"location":"Basal body","reliability":"Supported"},{"location":"Flagellar centriole","reliability":"Supported"},{"location":"Nucleoplasm","reliability":"Additional"},{"location":"Golgi apparatus","reliability":"Additional"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"retina","ntpm":26.9}],"url":"https://www.proteinatlas.org/search/FAM161A"},"hgnc":{"alias_symbol":["FLJ13305"],"prev_symbol":["RP28"]},"alphafold":{"accession":"Q3B820","domains":[{"cath_id":"1.20.5","chopping":"522-553","consensus_level":"medium","plddt":91.4644,"start":522,"end":553},{"cath_id":"1.10.287","chopping":"554-593","consensus_level":"medium","plddt":88.889,"start":554,"end":593}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q3B820","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q3B820-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q3B820-F1-predicted_aligned_error_v6.png","plddt_mean":66.38},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=FAM161A","jax_strain_url":"https://www.jax.org/strain/search?query=FAM161A"},"sequence":{"accession":"Q3B820","fasta_url":"https://rest.uniprot.org/uniprotkb/Q3B820.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q3B820/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q3B820"}},"corpus_meta":[{"pmid":"20705279","id":"PMC_20705279","title":"Homozygosity 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D2S286 on chromosome 2p11-p15 in an Indian family.","date":"1999","source":"Journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/10507729","citation_count":28,"is_preprint":false},{"pmid":"33479377","id":"PMC_33479377","title":"A new mouse model for retinal degeneration due to Fam161a deficiency.","date":"2021","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/33479377","citation_count":23,"is_preprint":false},{"pmid":"32938956","id":"PMC_32938956","title":"Unique combination of clinical features in a large cohort of 100 patients with retinitis pigmentosa caused by FAM161A mutations.","date":"2020","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/32938956","citation_count":20,"is_preprint":false},{"pmid":"15215745","id":"PMC_15215745","title":"Confirmation of linkage and refinement of the RP28 locus for autosomal recessive retinitis pigmentosa on chromosome 2p14-p15 in an Indian family.","date":"2004","source":"Molecular 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the FAM161A gene causing autosomal recessive retinitis pigmentosa in the Indian population.","date":"2015","source":"Journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/26246154","citation_count":12,"is_preprint":false},{"pmid":"26574802","id":"PMC_26574802","title":"A Nonsense Mutation in FAM161A Is a Recurrent Founder Allele in Dutch and Belgian Individuals With Autosomal Recessive Retinitis Pigmentosa.","date":"2015","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/26574802","citation_count":10,"is_preprint":false},{"pmid":"36420180","id":"PMC_36420180","title":"Retinal Structure and Function in a Knock-in Mouse Model for the FAM161A-p.Arg523∗ Human Nonsense Pathogenic Variant.","date":"2022","source":"Ophthalmology science","url":"https://pubmed.ncbi.nlm.nih.gov/36420180","citation_count":9,"is_preprint":false},{"pmid":"26113502","id":"PMC_26113502","title":"Diverse clinical phenotypes associated with a nonsense mutation 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\"Immunofluorescence, immunohistochemistry, siRNA knockdown with ciliary assembly readout\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal localization experiments across multiple species, siRNA knockdown with defined cellular phenotype, replicated by independent lab (PMID:22791751)\",\n      \"pmids\": [\"22940612\", \"22791751\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"FAM161A directly binds microtubules; overexpressed FAM161A associates with microtubules during interphase and mitosis and increases microtubule acetylation and stabilization. The evolutionarily conserved C-terminal UPF0564 domain mediates microtubule binding.\",\n      \"method\": \"Overexpression in cultured cells, immunofluorescence for microtubule co-localization, tubulin acetylation assay, domain deletion analysis\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single lab, overexpression system, multiple readouts (co-localization, acetylation, domain mapping) but no in vitro reconstitution with purified protein\",\n      \"pmids\": [\"22791751\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"The UPF0564 domain of FAM161A mediates homo- and heterotypic interaction with FAM161B, as well as binding to ciliopathy-associated proteins lebercilin, CEP290, OFD1, and SDCCAG8, as demonstrated by yeast two-hybrid and pull-down experiments in cultured cells and bovine retinal extracts.\",\n      \"method\": \"Yeast two-hybrid, pull-down assays in cultured cells and bovine retinal extracts\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — interactions validated by orthogonal methods (Y2H + pull-down) in two independent labs using native tissue (bovine retina) and cultured cells\",\n      \"pmids\": [\"22940612\", \"22791751\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"In Fam161a gene-trap mice lacking the C-terminal domain, the connecting cilium is significantly shortened, ciliary microtubule doublets are spread, and outer segment disk organization is disturbed. Interactors lebercilin and Cep290 are mislocalized to the basal body/proximal connecting cilium, and outer segment cargo proteins opsin and rds/peripherin 2 are misrouted, indicating the C-terminal domain is required for molecular delivery into the outer segment cilium.\",\n      \"method\": \"Gene-trap mouse model, electron microscopy, immunohistochemistry, western blot, ERG\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo genetic loss-of-function with multiple orthogonal structural and functional readouts (EM, IHC, ERG), defined pathway placement of cargo misrouting\",\n      \"pmids\": [\"24833722\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Yeast two-hybrid screening of human and bovine retinal cDNA libraries using FAM161A fragments as bait identified 53 interactors enriched in ciliary, Golgi apparatus, centrosomal, and microtubule network proteins, including AKAP9, FIP3, GOLGA3, KIFC3, KLC2, PDE4DIP, NIN, and TRIP11. Key interactions were validated by co-immunoprecipitation and proximity ligation assay, placing FAM161A as a member of the Golgi-centrosomal interactome.\",\n      \"method\": \"Yeast two-hybrid (cDNA library screen), co-immunoprecipitation, proximity ligation assay\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Y2H screen validated by orthogonal methods (Co-IP + PLA) in a single lab with native retinal tissue used as library source\",\n      \"pmids\": [\"25749990\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"FAM161A localization follows the centrosome during all stages of mitosis, suggesting compartmentalization related to centrosomal function during cell cycle progression as well as ciliary basal body function in G0.\",\n      \"method\": \"Cell cycle staging with immunofluorescence localization of FAM161A relative to centrosomal markers\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single method (immunofluorescence), no functional perturbation to test consequence of centrosomal localization\",\n      \"pmids\": [\"25749990\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Mutant FAM161A transcripts harboring nonsense mutations are actively degraded by nonsense-mediated mRNA decay (NMD) in patient-derived lymphoblasts, indicating that the disease mechanism involves FAM161A protein deficiency rather than production of a truncated protein.\",\n      \"method\": \"Analysis of FAM161A mRNA levels in cultured lymphoblasts from patients with nonsense mutations\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single molecular method in patient-derived cells, no NMD inhibitor control reported in abstract\",\n      \"pmids\": [\"24651477\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Structural bioinformatics analysis predicts FAM161A is a homologue of the microtubule nucleation factor TPX2, with three copies of the extended loop element and one short helix homologous to the TPX2 microtubule-nucleating elements, suggesting FAM161A binds microtubules in the same way as TPX2.\",\n      \"method\": \"Computational profile-profile homology search (PSI-BLAST, HHblits, HHpred), multiple sequence alignment\",\n      \"journal\": \"F1000Research\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — purely computational prediction, no experimental validation reported\",\n      \"pmids\": [\"33093951\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"C8orf37 physically interacts with FAM161A; the N-terminal region of C8orf37 binds to residues 341–517 within the UPF0564 domain of FAM161A. Both proteins co-localize at the ciliary base of photoreceptors in marmoset retina.\",\n      \"method\": \"Yeast two-hybrid screen, co-immunofluorescence, proximity ligation assay (PLA) in marmoset retinal sections and HEK293 cells, interaction domain mapping\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Y2H validated by PLA and co-localization in native tissue (marmoset retina), domain mapping performed; single lab\",\n      \"pmids\": [\"36233334\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"FAM161A expression in the retina is transcriptionally regulated by the photoreceptor transcription factor CRX, as demonstrated by chromatin immunoprecipitation showing CRX binding to the Fam161a promoter and organotypic reporter assays in explanted retinas.\",\n      \"method\": \"Chromatin immunoprecipitation (ChIP), organotypic retinal explant reporter assays\",\n      \"journal\": \"American journal of human genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — two orthogonal methods (ChIP + reporter assay) in a single study establishing FAM161A as a CRX transcriptional target\",\n      \"pmids\": [\"20705278\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In Fam161a-deficient mice, gene augmentation using AAV vectors expressing both the long (exon 4-containing) and short isoforms of human FAM161A under a weak promoter (FCBR1-F0.4) restored FAM161A localization to the connecting cilium and improved retinal function, whereas strong-promoter vectors or single-isoform delivery did not enhance retinal function despite improving cell survival, establishing that precise dosing and delivery of both isoforms is required for functional rescue.\",\n      \"method\": \"Subretinal AAV injection in Fam161a KO mice, ERG, OCT, immunohistochemistry, comparison of multiple vector/promoter/isoform combinations\",\n      \"journal\": \"EMBO molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo rescue experiment with multiple vector comparisons and functional readout (ERG), single lab but rigorous multi-condition design\",\n      \"pmids\": [\"38504136\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"FAM161A is a centrosomal-ciliary microtubule-associated protein that localizes to the photoreceptor connecting cilium and basal body, where its C-terminal UPF0564 domain mediates direct microtubule binding (promoting acetylation and stabilization), homo/heterotypic interactions with FAM161B, and binding to ciliopathy proteins (lebercilin, CEP290, OFD1, SDCCAG8, C8orf37); it is also a member of the Golgi-centrosomal interactome; loss of its C-terminal domain in vivo disrupts connecting cilium architecture, mislocalizes ciliary proteins, causes misrouting of outer segment cargo (opsin, peripherin-2), and leads to progressive photoreceptor degeneration, while its retinal expression is transcriptionally controlled by CRX.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"FAM161A is a centrosomal and ciliary microtubule-associated protein that organizes the photoreceptor connecting cilium and basal body to support outer segment biogenesis and protein delivery [#0, #3]. Through its evolutionarily conserved C-terminal UPF0564 domain it binds microtubules directly, promoting their acetylation and stabilization, and engages a network of ciliopathy-associated proteins including FAM161B, lebercilin, CEP290, OFD1, SDCCAG8, and C8orf37 [#1, #2, #8]. Beyond its ciliary role, FAM161A is a member of the Golgi-centrosomal interactome and tracks with the centrosome throughout mitosis, interacting with centrosomal and microtubule-network proteins such as AKAP9, NIN, PDE4DIP, KIFC3, and TRIP11 [#4, #5]. In vivo loss of the C-terminal domain shortens the connecting cilium, splays ciliary microtubule doublets, mislocalizes lebercilin and Cep290, and misroutes outer segment cargo (opsin and peripherin-2), establishing this domain as essential for molecular delivery into the outer segment [#3]. Its retinal expression is transcriptionally driven by the photoreceptor factor CRX [#9], and disease-associated nonsense alleles are eliminated by nonsense-mediated decay, indicating that pathology arises from protein deficiency [#6]; gene augmentation restoring both FAM161A isoforms at controlled dosage rescues connecting-cilium localization and retinal function in deficient mice [#10].\",\n  \"teleology\": [\n    {\n      \"year\": 2012,\n      \"claim\": \"Establishing where FAM161A acts and whether it is functionally required for cilia answered the first question of its cellular role.\",\n      \"evidence\": \"Immunofluorescence/immunohistochemistry across human, mouse and rat plus siRNA knockdown with a ciliary assembly readout in cultured cells\",\n      \"pmids\": [\"22940612\", \"22791751\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Does not define the molecular activity underlying ciliogenesis defect\", \"Connecting-cilium versus basal-body specific functions not separated\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Identifying direct microtubule binding via the UPF0564 domain provided a candidate biochemical mechanism for FAM161A's ciliary structural role.\",\n      \"evidence\": \"Overexpression in cultured cells with microtubule co-localization, tubulin acetylation assays, and domain-deletion mapping\",\n      \"pmids\": [\"22791751\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No in vitro reconstitution with purified protein\", \"Acetylation/stabilization shown in overexpression, not endogenous setting\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Mapping UPF0564-mediated interactions placed FAM161A within a ciliopathy protein network at the connecting cilium.\",\n      \"evidence\": \"Yeast two-hybrid and pull-down assays in cultured cells and bovine retinal extracts\",\n      \"pmids\": [\"22940612\", \"22791751\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Hierarchy and stoichiometry of the interaction network not resolved\", \"Functional consequence of each interaction not tested\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Demonstrating CRX control of FAM161A transcription connected its expression to the photoreceptor gene regulatory program.\",\n      \"evidence\": \"Chromatin immunoprecipitation and organotypic retinal explant reporter assays\",\n      \"pmids\": [\"20705278\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Other regulators of FAM161A not addressed\", \"Isoform-specific transcriptional control not examined\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"In vivo deletion of the C-terminal domain established that FAM161A is required for connecting-cilium architecture and for routing cargo into the outer segment.\",\n      \"evidence\": \"Gene-trap mouse model analyzed by electron microscopy, immunohistochemistry, western blot, and ERG\",\n      \"pmids\": [\"24833722\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism by which cargo (opsin, peripherin-2) is sorted not defined\", \"Distinguishes C-terminal requirement but not roles of other regions\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"A retinal interactome screen extended FAM161A beyond the cilium into a Golgi-centrosomal network.\",\n      \"evidence\": \"Yeast two-hybrid cDNA library screen validated by co-immunoprecipitation and proximity ligation assay\",\n      \"pmids\": [\"25749990\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional significance of Golgi-centrosomal partners untested\", \"Validated only a subset of 53 candidate interactors\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Tracking FAM161A with the centrosome through mitosis raised the possibility of a cell-cycle role distinct from its G0 ciliary function.\",\n      \"evidence\": \"Cell-cycle staged immunofluorescence relative to centrosomal markers\",\n      \"pmids\": [\"25749990\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No functional perturbation to test mitotic consequence\", \"Single method without orthogonal validation\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Showing NMD degradation of nonsense alleles clarified that disease results from protein loss rather than a dominant truncated product.\",\n      \"evidence\": \"FAM161A mRNA level analysis in patient-derived lymphoblasts\",\n      \"pmids\": [\"24651477\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No NMD-inhibitor control reported\", \"Limited to nonsense mutations, not other allele classes\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"A structural-homology prediction proposed that FAM161A binds microtubules in a TPX2-like manner, offering a mechanistic hypothesis for its tubulin interaction.\",\n      \"evidence\": \"Computational profile-profile homology search and multiple sequence alignment\",\n      \"pmids\": [\"33093951\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Purely computational with no experimental validation\", \"Predicted nucleation activity not tested biochemically\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Identifying C8orf37 as a UPF0564-domain partner co-localized at the ciliary base extended FAM161A's ciliopathy interaction map.\",\n      \"evidence\": \"Yeast two-hybrid, co-immunofluorescence, PLA in marmoset retina and HEK293 cells, with interaction domain mapping\",\n      \"pmids\": [\"36233334\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of the C8orf37 interaction not established\", \"Single lab without reciprocal in vivo validation\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Gene-augmentation rescue defined that restoring both FAM161A isoforms at controlled dosage is necessary for functional recovery, addressing therapeutic requirements.\",\n      \"evidence\": \"Subretinal AAV delivery in Fam161a KO mice with ERG, OCT, IHC across multiple vector/promoter/isoform combinations\",\n      \"pmids\": [\"38504136\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Distinct functional roles of long versus short isoforms not mechanistically resolved\", \"Single-lab demonstration in mouse only\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The biochemical mechanism by which FAM161A engages microtubules and directs outer-segment cargo trafficking remains undefined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No reconstituted in vitro microtubule-binding/nucleation assay with purified FAM161A\", \"Mechanism linking the interaction network to cargo sorting not established\", \"Isoform-specific molecular functions unresolved\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [1, 2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005929\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [0, 4, 5]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [1, 4]},\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"R-HSA-9709957\", \"supporting_discovery_ids\": [3, 10]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"FAM161B\", \"LCA5\", \"CEP290\", \"OFD1\", \"SDCCAG8\", \"C8orf37\", \"AKAP9\", \"NIN\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"faith_supported":5,"faith_total":5,"faith_pct":100.0}}