{"gene":"SLAIN2","run_date":"2026-06-10T07:46:32","timeline":{"discoveries":[{"year":2011,"finding":"SLAIN2 C-terminal domain binds end-binding proteins (EBs), cytoplasmic linker proteins (CLIPs), and CLIP-associated proteins (CLASPs), while its N-terminal domain interacts with ch-TOG (mammalian homologue of XMAP215 microtubule polymerase). Through these multiple interactions, SLAIN2 enhances ch-TOG accumulation at microtubule plus ends and strongly stimulates processive microtubule polymerization in interphase cells.","method":"Co-immunoprecipitation, pulldown assays, domain mapping, live-cell imaging of microtubule dynamics, RNAi knockdown with microtubule polymerization readout","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, domain-level interaction mapping, functional knockdown with defined cellular phenotype, replicated across multiple orthogonal methods in a single rigorous study","pmids":["21646404"],"is_preprint":false},{"year":2011,"finding":"During mitosis, SLAIN2 becomes highly phosphorylated and its interactions with EBs and ch-TOG are inhibited, providing a cell cycle-specific mechanism for downregulating processive microtubule polymerization in mitosis.","method":"Phosphorylation analysis, Co-immunoprecipitation across cell cycle stages, western blot","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — demonstrated in a single rigorous study with Co-IP and phosphorylation assays; mitotic regulation shown but kinase not identified","pmids":["21646404"],"is_preprint":false},{"year":2011,"finding":"Depletion or disruption of the SLAIN2–ch-TOG complex leads to disorganization of the radial microtubule array in interphase cells.","method":"RNAi knockdown, dominant-negative overexpression, immunofluorescence imaging of microtubule organization","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function with defined cellular phenotype, multiple approaches (RNAi + dominant-negative), replicated in multiple cell types","pmids":["21646404"],"is_preprint":false},{"year":2012,"finding":"SLAIN2 (and SLAIN1) are targeted to microtubule plus tips through interaction with EB family members, recruit ch-TOG to plus ends, and promote persistent microtubule growth; disruption of the SLAIN–ch-TOG complex in primary rat hippocampal neurons by RNAi knockdown or dominant-negative approach increases catastrophe frequency and inhibits axon extension during neuronal development.","method":"RNAi knockdown, dominant-negative approach, live-cell imaging of microtubule dynamics, axon length measurement in primary neurons","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function with defined neuronal phenotype using two orthogonal methods (RNAi and dominant-negative), replicating and extending findings from the original SLAIN2 characterization study","pmids":["23077057"],"is_preprint":false},{"year":2016,"finding":"SLAIN2 suppresses microtubule catastrophes (not Rho GTPase activity, trafficking, or focal adhesion formation), which determines microtubule resistance to compression and pseudopod elongation during mesenchymal cell invasion in 3D matrices; SLAIN2 inactivation does not affect 2D cell migration but is essential for mesenchymal cell invasion in 3D culture and in a mouse cancer model.","method":"RNAi knockdown, 3D invasion assays, mouse cancer model, Rho GTPase activity assays, trafficking assays, focal adhesion analysis, live microtubule dynamics imaging","journal":"Developmental cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function with defined invasion phenotype, multiple orthogonal mechanistic exclusions, validated in both in vitro and in vivo models","pmids":["27939686"],"is_preprint":false},{"year":2017,"finding":"The minimal protein binding domains of SLAIN2 in complexes with CLASP2 and ch-TOG were characterized using cross-linking mass spectrometry (XL-MS) combined with deletion analysis, identifying distance restraints between interacting residues and efficiently guiding design of minimal interaction fragments.","method":"Cross-linking mass spectrometry (XL-MS), deletion analysis, biochemical binding assays","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — in vitro XL-MS with deletion mapping provides structural-level binding domain information in a single lab study","pmids":["29044157"],"is_preprint":false},{"year":2020,"finding":"SLAIN2 localizes to the pericentriolar material at the proximal end of centrioles (in addition to microtubule plus ends); proximity-interaction (BioID) mapping revealed extensive interactions with centriole duplication, ciliogenesis, and microtubule-associated proteins.","method":"High-resolution fluorescence imaging, BioID proximity labeling followed by mass spectrometry","journal":"Turkish journal of biology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — direct localization by imaging and proximity interactome by BioID in a single study; functional consequence of centrosomal localization not experimentally validated","pmids":["32256142"],"is_preprint":false},{"year":2017,"finding":"RARα protein in human platelets directly binds SLAIN2 mRNA at consensus RARα binding sites in its 5' and 3' UTRs, and treatment with all-trans retinoic acid (atRA) releases RARα from SLAIN2 mRNA, suggesting RARα exerts translational control over SLAIN2 in anucleate platelets.","method":"RNA immunoprecipitation followed by next-generation sequencing (RIP-seq), targeted RIP, UTR binding site analysis, western blot","journal":"Journal of thrombosis and haemostasis","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct RNA-protein binding shown by RIP-seq and targeted RIP with pharmacological perturbation, single lab study","pmids":["28981191"],"is_preprint":false},{"year":2006,"finding":"SLAIN2 and its paralog SLAIN1 comprise a novel family of structurally unique proteins conserved throughout vertebrate evolution; SLAIN1 and SLAIN2 share a conserved domain architecture distinct from other known protein families.","method":"Comparative transcriptional profiling of mouse and human ES cells, bioinformatic sequence analysis","journal":"Developmental biology","confidence":"Low","confidence_rationale":"Tier 4 / Weak — computational/expression-based identification of a gene family with no direct mechanistic experiment on SLAIN2 protein function","pmids":["16546155"],"is_preprint":false}],"current_model":"SLAIN2 is a microtubule plus-end tracking protein (+TIP) whose C-terminal domain binds EB proteins, CLIPs, and CLASPs, while its N-terminal domain recruits the microtubule polymerase ch-TOG to growing microtubule plus ends, together strongly stimulating processive microtubule polymerization; during mitosis, SLAIN2 is hyperphosphorylated and its interactions with EBs and ch-TOG are disrupted, providing cell cycle-dependent regulation of microtubule growth, and SLAIN2-mediated catastrophe suppression is specifically required for 3D mesenchymal cell invasion and axonal development in neurons."},"narrative":{"mechanistic_narrative":"SLAIN2 is a microtubule plus-end tracking protein (+TIP) that promotes processive microtubule polymerization by serving as a molecular hub linking end-binding proteins to the microtubule polymerase ch-TOG [PMID:21646404]. Its C-terminal domain binds EBs, CLIPs, and CLASPs, while its N-terminal domain engages ch-TOG, so that SLAIN2 enhances ch-TOG accumulation at growing plus ends and suppresses microtubule catastrophes [PMID:21646404, PMID:29044157]; loss of the SLAIN2–ch-TOG complex disorganizes the interphase radial microtubule array [PMID:21646404]. This catastrophe-suppressing activity is cell-cycle regulated: during mitosis SLAIN2 is hyperphosphorylated and its interactions with EBs and ch-TOG are disrupted, downregulating processive growth [PMID:21646404]. The same activity is co-opted in specific physiological contexts — SLAIN2 is required for persistent plus-end growth supporting axon extension in developing neurons [PMID:23077057] and, by conferring microtubule resistance to compression, for pseudopod elongation during 3D mesenchymal cell invasion in vitro and in a mouse cancer model, independently of Rho GTPase activity, trafficking, or focal adhesions [PMID:27939686]. SLAIN2 additionally localizes to pericentriolar material at the proximal end of centrioles [PMID:32256142].","teleology":[{"year":2006,"claim":"Before any functional role was known, SLAIN2 was first identified as one of a novel, structurally distinct vertebrate-conserved gene family, establishing it as a defined protein worth characterizing.","evidence":"Comparative transcriptional profiling of mouse/human ES cells and bioinformatic sequence analysis","pmids":["16546155"],"confidence":"Low","gaps":["No direct experiment on SLAIN2 protein function","Domain architecture defined only computationally","No subcellular localization or interaction data"]},{"year":2011,"claim":"Resolved what SLAIN2 does molecularly: it acts as a +TIP adaptor that bridges EB/CLIP/CLASP plus-end machinery to the polymerase ch-TOG to drive processive microtubule growth, answering how a polymerase is loaded onto growing ends.","evidence":"Reciprocal Co-IP, pulldown, domain mapping, and live-cell microtubule dynamics with RNAi in interphase cells","pmids":["21646404"],"confidence":"High","gaps":["Stoichiometry and structural basis of the multi-partner complex not resolved","Whether EB and ch-TOG binding are simultaneous or competitive not defined"]},{"year":2011,"claim":"Addressed how SLAIN2 activity is temporally controlled, showing mitotic hyperphosphorylation disrupts its EB and ch-TOG interactions to switch off processive polymerization during cell division.","evidence":"Phosphorylation analysis and Co-IP across cell-cycle stages with western blot","pmids":["21646404"],"confidence":"Medium","gaps":["Responsible kinase not identified","Specific phosphosites not mapped","Functional consequence for spindle assembly not tested"]},{"year":2011,"claim":"Established the cellular consequence of SLAIN2 loss — disorganization of the radial microtubule array — linking molecular catastrophe suppression to cytoskeletal architecture.","evidence":"RNAi knockdown and dominant-negative overexpression with immunofluorescence imaging of microtubule organization","pmids":["21646404"],"confidence":"High","gaps":["Downstream effects on organelle positioning or polarity not examined"]},{"year":2012,"claim":"Extended the +TIP role to a physiological context, showing SLAIN-mediated catastrophe suppression sustains plus-end growth required for axon extension in neurons.","evidence":"RNAi and dominant-negative in primary rat hippocampal neurons with live microtubule imaging and axon length measurement","pmids":["23077057"],"confidence":"High","gaps":["In vivo neuronal requirement not tested","Relative contributions of SLAIN1 vs SLAIN2 not separated"]},{"year":2016,"claim":"Demonstrated a disease-relevant function by isolating catastrophe suppression as the operative mechanism conferring microtubule mechanical resistance needed for 3D mesenchymal invasion, while excluding alternative pathways.","evidence":"RNAi, 3D invasion assays, mouse cancer model, plus exclusion of Rho GTPase, trafficking, and focal adhesion contributions","pmids":["27939686"],"confidence":"High","gaps":["Whether SLAIN2 is required in human tumors not established","No genetic/causative human cancer mutation shown"]},{"year":2017,"claim":"Provided structural-level definition of the SLAIN2 interaction interfaces with CLASP2 and ch-TOG, enabling design of minimal binding fragments.","evidence":"Cross-linking mass spectrometry with deletion analysis and biochemical binding assays","pmids":["29044157"],"confidence":"Medium","gaps":["No high-resolution atomic structure","Single-lab in vitro mapping"]},{"year":2017,"claim":"Revealed a non-cytoskeletal layer of SLAIN2 regulation — translational control of its mRNA by RARα in anucleate platelets, modulated by retinoic acid.","evidence":"RIP-seq, targeted RIP, UTR binding site analysis, and western blot in human platelets","pmids":["28981191"],"confidence":"Medium","gaps":["Functional role of SLAIN2 in platelets not defined","Direct demonstration of translational repression not shown"]},{"year":2020,"claim":"Identified a second localization for SLAIN2 at pericentriolar material and mapped a proximity interactome enriched for centriole and ciliogenesis proteins, broadening its potential cellular roles beyond plus ends.","evidence":"High-resolution imaging and BioID proximity labeling with mass spectrometry","pmids":["32256142"],"confidence":"Medium","gaps":["Functional consequence of centrosomal localization not validated","BioID proximity does not confirm direct binding"]},{"year":null,"claim":"The identity of the mitotic kinase regulating SLAIN2, the functional significance of its centrosomal localization, and its role in platelets remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["Mitotic kinase and phosphosites unidentified","Centriolar function untested","Platelet/RARα axis function unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,3,5]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[0,2]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,4]}],"localization":[{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[0,2]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[6]}],"pathway":[{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[1]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[3]}],"complexes":[],"partners":["CKAP5","MAPRE1","CLASP2","CLIP1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9P270","full_name":"SLAIN motif-containing protein 2","aliases":[],"length_aa":581,"mass_kda":62.5,"function":"Binds to the plus end of microtubules and regulates microtubule dynamics and microtubule organization. Promotes cytoplasmic microtubule nucleation and elongation. Required for normal structure of the microtubule cytoskeleton during interphase","subcellular_location":"Cytoplasm, cytoskeleton","url":"https://www.uniprot.org/uniprotkb/Q9P270/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/SLAIN2","classification":"Not Classified","n_dependent_lines":7,"n_total_lines":1208,"dependency_fraction":0.005794701986754967},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CKAP5","stoichiometry":0.2},{"gene":"TUBA1B","stoichiometry":0.2},{"gene":"TUBB4B","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/SLAIN2","total_profiled":1310},"omim":[{"mim_id":"610492","title":"SLAIN MOTIF FAMILY, MEMBER 2; SLAIN2","url":"https://www.omim.org/entry/610492"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Centrosome","reliability":"Supported"},{"location":"Cytosol","reliability":"Supported"},{"location":"Primary cilium tip","reliability":"Additional"},{"location":"Basal body","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/SLAIN2"},"hgnc":{"alias_symbol":["FLJ21611"],"prev_symbol":["KIAA1458"]},"alphafold":{"accession":"Q9P270","domains":[],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9P270","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9P270-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9P270-F1-predicted_aligned_error_v6.png","plddt_mean":53.72},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SLAIN2","jax_strain_url":"https://www.jax.org/strain/search?query=SLAIN2"},"sequence":{"accession":"Q9P270","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9P270.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9P270/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9P270"}},"corpus_meta":[{"pmid":"21646404","id":"PMC_21646404","title":"SLAIN2 links microtubule plus end-tracking proteins and controls microtubule growth in interphase.","date":"2011","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/21646404","citation_count":107,"is_preprint":false},{"pmid":"30797712","id":"PMC_30797712","title":"MALAT1 sponges miR-106b-5p to promote the invasion and metastasis of colorectal cancer via SLAIN2 enhanced microtubules mobility.","date":"2019","source":"EBioMedicine","url":"https://pubmed.ncbi.nlm.nih.gov/30797712","citation_count":95,"is_preprint":false},{"pmid":"27939686","id":"PMC_27939686","title":"Mesenchymal Cell Invasion Requires Cooperative Regulation of Persistent Microtubule Growth by SLAIN2 and CLASP1.","date":"2016","source":"Developmental cell","url":"https://pubmed.ncbi.nlm.nih.gov/27939686","citation_count":59,"is_preprint":false},{"pmid":"16546155","id":"PMC_16546155","title":"Transcriptional profiling of mouse and human ES cells identifies SLAIN1, a novel stem cell gene.","date":"2006","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/16546155","citation_count":44,"is_preprint":false},{"pmid":"23077057","id":"PMC_23077057","title":"Microtubule plus-end tracking proteins SLAIN1/2 and ch-TOG promote axonal development.","date":"2012","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/23077057","citation_count":40,"is_preprint":false},{"pmid":"28981191","id":"PMC_28981191","title":"Retinoic acid receptor-α regulates synthetic events in human platelets.","date":"2017","source":"Journal of thrombosis and haemostasis : JTH","url":"https://pubmed.ncbi.nlm.nih.gov/28981191","citation_count":21,"is_preprint":false},{"pmid":"29044157","id":"PMC_29044157","title":"Facilitating identification of minimal protein binding domains by cross-linking mass spectrometry.","date":"2017","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/29044157","citation_count":18,"is_preprint":false},{"pmid":"37817544","id":"PMC_37817544","title":"Circ-Slain2 Alleviates Cartilage Degradation and Inflammation of TMJOA.","date":"2023","source":"Journal of dental research","url":"https://pubmed.ncbi.nlm.nih.gov/37817544","citation_count":12,"is_preprint":false},{"pmid":"39245941","id":"PMC_39245941","title":"Joint genotype and ancestry analysis identify novel loci associated with atopic dermatitis in African American population.","date":"2024","source":"HGG advances","url":"https://pubmed.ncbi.nlm.nih.gov/39245941","citation_count":5,"is_preprint":false},{"pmid":"32256142","id":"PMC_32256142","title":"Proximity mapping of the microtubule plus-end tracking protein SLAIN2 using the BioID approach.","date":"2020","source":"Turkish journal of biology = Turk biyoloji dergisi","url":"https://pubmed.ncbi.nlm.nih.gov/32256142","citation_count":4,"is_preprint":false},{"pmid":"37741612","id":"PMC_37741612","title":"Slain2 attenuates brain injury following subarachnoid hemorrhage by controlling axonal microtubule structure in mice.","date":"2023","source":"Neuroscience letters","url":"https://pubmed.ncbi.nlm.nih.gov/37741612","citation_count":3,"is_preprint":false},{"pmid":"39069524","id":"PMC_39069524","title":"Exploring circular RNAs as biomarkers for Parkinson's disease and their expression changes after aerobic exercise rehabilitation.","date":"2024","source":"Functional & integrative genomics","url":"https://pubmed.ncbi.nlm.nih.gov/39069524","citation_count":2,"is_preprint":false},{"pmid":"36979179","id":"PMC_36979179","title":"Dynamic Regulation Genes at Microtubule Plus Ends: A Novel Class of Glioma Biomarkers.","date":"2023","source":"Biology","url":"https://pubmed.ncbi.nlm.nih.gov/36979179","citation_count":2,"is_preprint":false},{"pmid":"35848598","id":"PMC_35848598","title":"Identification of key candidate genes for wing length-related traits by whole-genome resequencing in 772 geese.","date":"2022","source":"British poultry science","url":"https://pubmed.ncbi.nlm.nih.gov/35848598","citation_count":2,"is_preprint":false},{"pmid":"41986449","id":"PMC_41986449","title":"Identification of biomarkers in myocardial hypertrophy and fibrosis via integrated transcriptomic and phosphoproteomic profiling.","date":"2026","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/41986449","citation_count":0,"is_preprint":false},{"pmid":"41646826","id":"PMC_41646826","title":"Genome wide association study meta-analysis of neuropathologic lesions of Alzheimer's disease and related dementias in a multi-site autopsy cohort.","date":"2026","source":"medRxiv : the preprint server for health sciences","url":"https://pubmed.ncbi.nlm.nih.gov/41646826","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":10582,"output_tokens":2176,"usd":0.032193,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9308,"output_tokens":2929,"usd":0.059882,"stage2_stop_reason":"end_turn"},"total_usd":0.092075,"stage1_batch_id":"msgbatch_013LWZZT6MWaqB9qyTSeQBmU","stage2_batch_id":"msgbatch_0194ZzQaTGNpruoNJBbEMbt3","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2011,\n      \"finding\": \"SLAIN2 C-terminal domain binds end-binding proteins (EBs), cytoplasmic linker proteins (CLIPs), and CLIP-associated proteins (CLASPs), while its N-terminal domain interacts with ch-TOG (mammalian homologue of XMAP215 microtubule polymerase). Through these multiple interactions, SLAIN2 enhances ch-TOG accumulation at microtubule plus ends and strongly stimulates processive microtubule polymerization in interphase cells.\",\n      \"method\": \"Co-immunoprecipitation, pulldown assays, domain mapping, live-cell imaging of microtubule dynamics, RNAi knockdown with microtubule polymerization readout\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, domain-level interaction mapping, functional knockdown with defined cellular phenotype, replicated across multiple orthogonal methods in a single rigorous study\",\n      \"pmids\": [\"21646404\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"During mitosis, SLAIN2 becomes highly phosphorylated and its interactions with EBs and ch-TOG are inhibited, providing a cell cycle-specific mechanism for downregulating processive microtubule polymerization in mitosis.\",\n      \"method\": \"Phosphorylation analysis, Co-immunoprecipitation across cell cycle stages, western blot\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — demonstrated in a single rigorous study with Co-IP and phosphorylation assays; mitotic regulation shown but kinase not identified\",\n      \"pmids\": [\"21646404\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Depletion or disruption of the SLAIN2–ch-TOG complex leads to disorganization of the radial microtubule array in interphase cells.\",\n      \"method\": \"RNAi knockdown, dominant-negative overexpression, immunofluorescence imaging of microtubule organization\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function with defined cellular phenotype, multiple approaches (RNAi + dominant-negative), replicated in multiple cell types\",\n      \"pmids\": [\"21646404\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"SLAIN2 (and SLAIN1) are targeted to microtubule plus tips through interaction with EB family members, recruit ch-TOG to plus ends, and promote persistent microtubule growth; disruption of the SLAIN–ch-TOG complex in primary rat hippocampal neurons by RNAi knockdown or dominant-negative approach increases catastrophe frequency and inhibits axon extension during neuronal development.\",\n      \"method\": \"RNAi knockdown, dominant-negative approach, live-cell imaging of microtubule dynamics, axon length measurement in primary neurons\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function with defined neuronal phenotype using two orthogonal methods (RNAi and dominant-negative), replicating and extending findings from the original SLAIN2 characterization study\",\n      \"pmids\": [\"23077057\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"SLAIN2 suppresses microtubule catastrophes (not Rho GTPase activity, trafficking, or focal adhesion formation), which determines microtubule resistance to compression and pseudopod elongation during mesenchymal cell invasion in 3D matrices; SLAIN2 inactivation does not affect 2D cell migration but is essential for mesenchymal cell invasion in 3D culture and in a mouse cancer model.\",\n      \"method\": \"RNAi knockdown, 3D invasion assays, mouse cancer model, Rho GTPase activity assays, trafficking assays, focal adhesion analysis, live microtubule dynamics imaging\",\n      \"journal\": \"Developmental cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function with defined invasion phenotype, multiple orthogonal mechanistic exclusions, validated in both in vitro and in vivo models\",\n      \"pmids\": [\"27939686\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"The minimal protein binding domains of SLAIN2 in complexes with CLASP2 and ch-TOG were characterized using cross-linking mass spectrometry (XL-MS) combined with deletion analysis, identifying distance restraints between interacting residues and efficiently guiding design of minimal interaction fragments.\",\n      \"method\": \"Cross-linking mass spectrometry (XL-MS), deletion analysis, biochemical binding assays\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro XL-MS with deletion mapping provides structural-level binding domain information in a single lab study\",\n      \"pmids\": [\"29044157\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"SLAIN2 localizes to the pericentriolar material at the proximal end of centrioles (in addition to microtubule plus ends); proximity-interaction (BioID) mapping revealed extensive interactions with centriole duplication, ciliogenesis, and microtubule-associated proteins.\",\n      \"method\": \"High-resolution fluorescence imaging, BioID proximity labeling followed by mass spectrometry\",\n      \"journal\": \"Turkish journal of biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — direct localization by imaging and proximity interactome by BioID in a single study; functional consequence of centrosomal localization not experimentally validated\",\n      \"pmids\": [\"32256142\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"RARα protein in human platelets directly binds SLAIN2 mRNA at consensus RARα binding sites in its 5' and 3' UTRs, and treatment with all-trans retinoic acid (atRA) releases RARα from SLAIN2 mRNA, suggesting RARα exerts translational control over SLAIN2 in anucleate platelets.\",\n      \"method\": \"RNA immunoprecipitation followed by next-generation sequencing (RIP-seq), targeted RIP, UTR binding site analysis, western blot\",\n      \"journal\": \"Journal of thrombosis and haemostasis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct RNA-protein binding shown by RIP-seq and targeted RIP with pharmacological perturbation, single lab study\",\n      \"pmids\": [\"28981191\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"SLAIN2 and its paralog SLAIN1 comprise a novel family of structurally unique proteins conserved throughout vertebrate evolution; SLAIN1 and SLAIN2 share a conserved domain architecture distinct from other known protein families.\",\n      \"method\": \"Comparative transcriptional profiling of mouse and human ES cells, bioinformatic sequence analysis\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — computational/expression-based identification of a gene family with no direct mechanistic experiment on SLAIN2 protein function\",\n      \"pmids\": [\"16546155\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SLAIN2 is a microtubule plus-end tracking protein (+TIP) whose C-terminal domain binds EB proteins, CLIPs, and CLASPs, while its N-terminal domain recruits the microtubule polymerase ch-TOG to growing microtubule plus ends, together strongly stimulating processive microtubule polymerization; during mitosis, SLAIN2 is hyperphosphorylated and its interactions with EBs and ch-TOG are disrupted, providing cell cycle-dependent regulation of microtubule growth, and SLAIN2-mediated catastrophe suppression is specifically required for 3D mesenchymal cell invasion and axonal development in neurons.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SLAIN2 is a microtubule plus-end tracking protein (+TIP) that promotes processive microtubule polymerization by serving as a molecular hub linking end-binding proteins to the microtubule polymerase ch-TOG [#0]. Its C-terminal domain binds EBs, CLIPs, and CLASPs, while its N-terminal domain engages ch-TOG, so that SLAIN2 enhances ch-TOG accumulation at growing plus ends and suppresses microtubule catastrophes [#0, #5]; loss of the SLAIN2\\u2013ch-TOG complex disorganizes the interphase radial microtubule array [#2]. This catastrophe-suppressing activity is cell-cycle regulated: during mitosis SLAIN2 is hyperphosphorylated and its interactions with EBs and ch-TOG are disrupted, downregulating processive growth [#1]. The same activity is co-opted in specific physiological contexts \\u2014 SLAIN2 is required for persistent plus-end growth supporting axon extension in developing neurons [#3] and, by conferring microtubule resistance to compression, for pseudopod elongation during 3D mesenchymal cell invasion in vitro and in a mouse cancer model, independently of Rho GTPase activity, trafficking, or focal adhesions [#4]. SLAIN2 additionally localizes to pericentriolar material at the proximal end of centrioles [#6].\",\n  \"teleology\": [\n    {\n      \"year\": 2006,\n      \"claim\": \"Before any functional role was known, SLAIN2 was first identified as one of a novel, structurally distinct vertebrate-conserved gene family, establishing it as a defined protein worth characterizing.\",\n      \"evidence\": \"Comparative transcriptional profiling of mouse/human ES cells and bioinformatic sequence analysis\",\n      \"pmids\": [\"16546155\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No direct experiment on SLAIN2 protein function\", \"Domain architecture defined only computationally\", \"No subcellular localization or interaction data\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Resolved what SLAIN2 does molecularly: it acts as a +TIP adaptor that bridges EB/CLIP/CLASP plus-end machinery to the polymerase ch-TOG to drive processive microtubule growth, answering how a polymerase is loaded onto growing ends.\",\n      \"evidence\": \"Reciprocal Co-IP, pulldown, domain mapping, and live-cell microtubule dynamics with RNAi in interphase cells\",\n      \"pmids\": [\"21646404\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry and structural basis of the multi-partner complex not resolved\", \"Whether EB and ch-TOG binding are simultaneous or competitive not defined\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Addressed how SLAIN2 activity is temporally controlled, showing mitotic hyperphosphorylation disrupts its EB and ch-TOG interactions to switch off processive polymerization during cell division.\",\n      \"evidence\": \"Phosphorylation analysis and Co-IP across cell-cycle stages with western blot\",\n      \"pmids\": [\"21646404\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Responsible kinase not identified\", \"Specific phosphosites not mapped\", \"Functional consequence for spindle assembly not tested\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Established the cellular consequence of SLAIN2 loss \\u2014 disorganization of the radial microtubule array \\u2014 linking molecular catastrophe suppression to cytoskeletal architecture.\",\n      \"evidence\": \"RNAi knockdown and dominant-negative overexpression with immunofluorescence imaging of microtubule organization\",\n      \"pmids\": [\"21646404\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Downstream effects on organelle positioning or polarity not examined\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Extended the +TIP role to a physiological context, showing SLAIN-mediated catastrophe suppression sustains plus-end growth required for axon extension in neurons.\",\n      \"evidence\": \"RNAi and dominant-negative in primary rat hippocampal neurons with live microtubule imaging and axon length measurement\",\n      \"pmids\": [\"23077057\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo neuronal requirement not tested\", \"Relative contributions of SLAIN1 vs SLAIN2 not separated\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Demonstrated a disease-relevant function by isolating catastrophe suppression as the operative mechanism conferring microtubule mechanical resistance needed for 3D mesenchymal invasion, while excluding alternative pathways.\",\n      \"evidence\": \"RNAi, 3D invasion assays, mouse cancer model, plus exclusion of Rho GTPase, trafficking, and focal adhesion contributions\",\n      \"pmids\": [\"27939686\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether SLAIN2 is required in human tumors not established\", \"No genetic/causative human cancer mutation shown\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Provided structural-level definition of the SLAIN2 interaction interfaces with CLASP2 and ch-TOG, enabling design of minimal binding fragments.\",\n      \"evidence\": \"Cross-linking mass spectrometry with deletion analysis and biochemical binding assays\",\n      \"pmids\": [\"29044157\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No high-resolution atomic structure\", \"Single-lab in vitro mapping\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Revealed a non-cytoskeletal layer of SLAIN2 regulation \\u2014 translational control of its mRNA by RAR\\u03b1 in anucleate platelets, modulated by retinoic acid.\",\n      \"evidence\": \"RIP-seq, targeted RIP, UTR binding site analysis, and western blot in human platelets\",\n      \"pmids\": [\"28981191\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional role of SLAIN2 in platelets not defined\", \"Direct demonstration of translational repression not shown\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified a second localization for SLAIN2 at pericentriolar material and mapped a proximity interactome enriched for centriole and ciliogenesis proteins, broadening its potential cellular roles beyond plus ends.\",\n      \"evidence\": \"High-resolution imaging and BioID proximity labeling with mass spectrometry\",\n      \"pmids\": [\"32256142\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of centrosomal localization not validated\", \"BioID proximity does not confirm direct binding\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The identity of the mitotic kinase regulating SLAIN2, the functional significance of its centrosomal localization, and its role in platelets remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mitotic kinase and phosphosites unidentified\", \"Centriolar function untested\", \"Platelet/RAR\\u03b1 axis function unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 3, 5]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 4]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"CKAP5\", \"MAPRE1\", \"CLASP2\", \"CLIP1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}