Affinage

SYMPK

Symplekin · UniProt Q92797

Round 2 corrected
Length
1274 aa
Mass
141.1 kDa
Annotated
2026-04-28
113 papers in source corpus 12 papers cited in narrative 12 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

Symplekin (SYMPK) is a scaffold protein that organizes mRNA 3'-end processing and polyadenylation complexes by simultaneously binding CPSF, CstF-64, CPEB, and poly(A) polymerases (xGLD-2, Star-PAP), thereby coordinating both nuclear pre-mRNA cleavage/polyadenylation and cytoplasmic polyadenylation during oocyte maturation (PMID:15550246, PMID:10669729, PMID:18288197). Its yeast ortholog Pta1 is an essential subunit of the CPF/CF II complex required for mRNA 3'-end formation, snoRNA transcription termination, and alternative polyadenylation site selection, with distinct N-terminal and C-terminal domains mediating interactions with different processing subunits (PMID:10523662, PMID:19188448, PMID:19646984). Beyond canonical RNA processing, SYMPK regulates alternative splicing in male germ cells—where its loss causes meiotic synapsis and recombination defects leading to infertility—and localizes to the meiotic spindle in oocytes, interacting with KIF20A and NUMA1 to organize acentrosomal spindle architecture, with oocyte-specific knockout causing metaphase I arrest and female infertility (PMID:34434935, PMID:41520922). SYMPK also interacts with Oct4 through its DUF3453 domain to promote embryonic stem cell self-renewal and pluripotency (PMID:30801858).

Mechanistic history

Synthesis pass · year-by-year structured walk · 10 steps
  1. 1992 High

    Establishing that the symplekin ortholog Pta1 is an essential gene required for pre-tRNA processing in yeast revealed the first genetic link between this protein family and RNA maturation.

    Evidence UV mutagenesis, complementation cloning, and gene disruption in S. cerevisiae

    PMID:1508188

    Open questions at the time
    • Mechanism of Pta1 action on pre-tRNA processing was unknown
    • Whether Pta1 functions in mRNA processing was not tested
  2. 1996 High

    Discovery of mammalian symplekin as a dual-residence protein present at tight junction plaques and in the nucleoplasm of all cell types established its unusual subcellular distribution and suggested nuclear functions beyond cell adhesion.

    Evidence Monoclonal antibody generation, cDNA cloning, immunofluorescence, and immunoelectron microscopy across epithelial and non-epithelial cells

    PMID:8769423

    Open questions at the time
    • Nuclear function was entirely unknown
    • Relationship to the yeast Pta1 ortholog was not recognized
  3. 1999 High

    Biochemical identification of Pta1 as a CF II subunit required for both endonucleolytic cleavage and polyadenylation of mRNA precursors established that the symplekin family directly participates in mRNA 3'-end formation.

    Evidence Protein sequencing of purified CF II, complementation of pta1 mutant extracts, co-immunoprecipitation with Pap1/Fip1/Yth1 in yeast

    PMID:10523662

    Open questions at the time
    • Whether human symplekin performs an equivalent role was unresolved
    • How Pta1 coordinates cleavage versus polyadenylation was unclear
  4. 2000 High

    Identification of human symplekin as a CstF-64 interactor co-isolating with CPSF and CstF extended the scaffold concept to mammalian polyadenylation, answering whether the yeast function was conserved.

    Evidence Yeast two-hybrid and co-immunoprecipitation from human cell extracts

    PMID:10669729

    Open questions at the time
    • Whether symplekin is catalytically active or purely a scaffold was unknown
    • Its role in cytoplasmic polyadenylation had not been examined
  5. 2004 High

    Demonstrating that symplekin scaffolds a cytoplasmic polyadenylation complex by bridging CPEB, CPSF, and xGLD-2 in Xenopus oocytes revealed a second, spatially distinct function for the protein in translational control during development.

    Evidence Depletion from Xenopus oocyte extracts, in vitro polyadenylation assays, co-immunoprecipitation with CPEB/CPSF/xGLD-2

    PMID:15550246

    Open questions at the time
    • Structural basis for simultaneous binding of multiple partners was not determined
    • Whether the scaffold role applies in somatic cell cytoplasm was untested
  6. 2008 High

    Identification of symplekin within the PtdIns4,5P2-regulated Star-PAP complex at nuclear speckles expanded its repertoire to signal-dependent 3'-end processing of stress-response mRNAs.

    Evidence Co-immunoprecipitation and co-localization of symplekin with Star-PAP and PIPKIα at nuclear speckles, functional mRNA processing assays

    PMID:18288197

    Open questions at the time
    • Direct contribution of symplekin versus other co-factors in Star-PAP target specificity was not dissected
    • How lipid signaling modulates symplekin within this complex was unclear
  7. 2009 High

    Domain dissection of yeast Pta1 showed that its N-terminus mediates snoRNA termination and Ssu72 phosphatase function while being dispensable for mRNA 3'-end processing, establishing a modular scaffold architecture with separable functions.

    Evidence N-terminal deletion analysis, degron-mediated depletion, in vitro cleavage/polyadenylation assays, and snoRNA termination assays in yeast

    PMID:19188448 PMID:19646984

    Open questions at the time
    • Whether mammalian symplekin has analogous modular domain organization was not tested
    • The mechanism by which Pta1 influences polyadenylation site choice remained indirect
  8. 2019 Medium

    Discovery that SYMPK interacts with Oct4 via its DUF3453 domain and promotes ESC self-renewal revealed a function beyond RNA processing, linking symplekin to the pluripotency transcriptional network.

    Evidence CRISPR/Cas9 knockout, overexpression, co-immunoprecipitation of SYMPK-Oct4, DUF3453 domain deletion, RNA-seq in mouse ESCs

    PMID:30801858

    Open questions at the time
    • Whether the Oct4 interaction is direct or mediated by RNA was not determined
    • Single-lab finding without independent replication
    • Mechanism linking DUF3453-Oct4 binding to transcriptional output was not resolved
  9. 2021 High

    Conditional knockout in male germ cells demonstrated that SYMPK regulates alternative splicing during spermatogenesis, with its loss causing synapsis and DSB repair defects and male infertility, extending symplekin's roles to splicing regulation.

    Evidence Two independent Cre-driven conditional knockouts in mouse germ cells, chromosome spreads, γH2AX/SYCP3 immunostaining, RNA-seq for alternative splicing

    PMID:34434935

    Open questions at the time
    • Whether splicing regulation is direct or indirect through altered 3'-end processing was not distinguished
    • Identity of direct splicing targets beyond Sun1 was incomplete
  10. 2026 High

    Oocyte-specific knockout and IP-MS revealed that SYMPK localizes to spindle microtubules after GVBD and interacts with KIF20A and NUMA1 to organize acentrosomal meiotic spindle architecture, explaining female infertility as metaphase I arrest from destabilized kinetochore-microtubule attachments.

    Evidence Oocyte-specific conditional knockout, live spindle imaging, IP-MS identifying KIF20A/NUMA1, SAC pharmacologic inhibition, immunofluorescence

    PMID:41520922

    Open questions at the time
    • Whether the spindle function is independent of symplekin's RNA processing role was not resolved
    • Direct binding surfaces for KIF20A and NUMA1 were not mapped
    • Whether this spindle role operates in mitotic cells was not examined

Open questions

Synthesis pass · forward-looking unresolved questions
  • A unifying structural and mechanistic model explaining how symplekin's scaffold domains simultaneously coordinate RNA processing, splicing regulation, spindle organization, and pluripotency maintenance remains unresolved.
  • No high-resolution structure of full-length symplekin or its complexes exists
  • Whether RNA processing and spindle functions are mechanistically coupled or independent has not been tested
  • The full repertoire of symplekin-dependent mRNA targets in mammalian somatic cells is unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 4 GO:0003723 RNA binding 3 GO:0008092 cytoskeletal protein binding 1
Localization
GO:0005634 nucleus 3 GO:0005654 nucleoplasm 1 GO:0005829 cytosol 1 GO:0005856 cytoskeleton 1 GO:0005886 plasma membrane 1
Pathway
R-HSA-8953854 Metabolism of RNA 7 R-HSA-1266738 Developmental Biology 2 R-HSA-1474165 Reproduction 2 R-HSA-74160 Gene expression (Transcription) 2 R-HSA-1640170 Cell Cycle 1
Partners
CPEB1CPSF1CSTF2KIF20ANUMA1PIP5K1APOU5F1TUT1
Complex memberships
CPEB cytoplasmic polyadenylation complexCPF/CF II (yeast 3'-end processing complex)CPSF/CstF polyadenylation complexStar-PAP complex

Evidence

Reading pass · 12 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1996 Symplekin was identified as a novel tight junction plaque protein localized to the cytoplasmic face of zonula occludens in polar epithelial cells and Sertoli cells. Critically, it was also found in the nucleoplasm of virtually all cell types, including those lacking tight junctions, establishing it as a dual-residence protein present at tight junction plaques and in the nucleus. Monoclonal antibody generation, cDNA cloning, light and electron microscopy, immunofluorescence localization across cell types The Journal of cell biology High 8769423
1992 Yeast PTA1 (ortholog of symplekin) was identified as an essential gene affecting pre-tRNA processing. The pta1-1 mutation caused accumulation of intron-containing pre-tRNAs and temperature-sensitive growth, and the gene encodes an 88 kDa protein of 785 amino acids with no previously identified homologs. UV-induced mutagenesis, complementation cloning, gene disruption, biochemical extract analysis of pre-tRNA processing Molecular and cellular biology High 1508188
1999 Yeast Pta1 (symplekin ortholog) is a subunit of CF II (Cleavage Factor II) and is required for both endonucleolytic cleavage and poly(A) addition of mRNA precursors. Pta1-containing CF II can be found in a stable complex with Pap1, Fip1, and Yth1 (polyadenylation factor I subunits), suggesting a large integrated 3'-end processing assembly in vivo. Protein sequencing, immunoreactivity, complementation of pta1 mutant extracts with purified CF II, coimmunoprecipitation Molecular and cellular biology High 10523662
2000 Human symplekin was identified as a novel component of the polyadenylation machinery through its interaction with CstF-64 (a subunit of Cleavage Stimulation Factor). Multiple polyadenylation factors including CstF, CPSF, and symplekin could be co-isolated as part of a large complex from cells, suggesting symplekin functions in assembly of the polyadenylation machinery. Yeast two-hybrid interaction mapping, co-immunoprecipitation from cell extracts, domain mapping of CstF subunit interactions Molecular and cellular biology High 10669729
2004 In Xenopus oocytes, symplekin serves as a scaffold protein essential for cytoplasmic polyadenylation. It binds both CPEB (the RNA-binding protein that specifies which mRNAs are polyadenylated) and CPSF (the factor recognizing the AAUAAA hexanucleotide), and is required to recruit xGLD-2 (an unconventional poly(A) polymerase) to form the active cytoplasmic polyadenylation complex. Depletion of symplekin blocks cytoplasmic polyadenylation. Co-immunoprecipitation, depletion from Xenopus oocyte extracts, rescue experiments, in vitro polyadenylation assays Cell High 15550246
2008 Symplekin was identified as a component of the nuclear Star-PAP (PIPKIα-regulated poly(A) polymerase) complex at nuclear speckles. This complex, regulated by PtdIns4,5P2, controls 3'-end formation of select stress-response mRNAs including haem oxygenase-1 mRNA. Symplekin co-localizes and co-immunoprecipitates with Star-PAP and PIPKIα. Co-immunoprecipitation, co-localization by fluorescence microscopy at nuclear speckles, mRNA 3'-end processing assays Nature High 18288197
2009 The N-terminal region of yeast Pta1 (symplekin ortholog) is required for snoRNA transcription termination and Ssu72 phosphatase function but is dispensable for pre-mRNA 3'-end processing. Different regions of Pta1 interact with distinct CPF subunits (Ssu72, Pti1, Ysh1), supporting the scaffold model in which Pta1 organizes the cleavage/polyadenylation factor (CPF) complex. N-terminal deletion analysis, degron-mediated depletion, in vitro cleavage/polyadenylation assays, co-immunoprecipitation of Pta1 with CPF subunits, snoRNA termination assays, RNA Pol II CTD phosphorylation analysis Molecular and cellular biology High 19188448
2009 Yeast Pta1 (symplekin ortholog) and Pcf11 are involved in alternative RNA 3'-end processing site selection. The pta1-1 mutation altered the predominance of KlCYC1 transcript isoforms, and mutation of an AU-rich element in the 3'-UTR of the target gene partially suppressed this effect, indicating Pta1 influences which polyadenylation site is chosen. Yeast mutant analysis, Northern blot of transcript isoforms, 3'-UTR mutation analysis, Pta1-td degron depletion strain FEBS letters Medium 19646984
2012 Yeast Swd2, a subunit of both the Set1/COMPASS histone methyltransferase complex and the APT (Associated with Pta1) transcription termination complex, is essential because of antagonism between these two complexes. APT (which contains Pta1/symplekin ortholog) requires Swd2 for recruitment to genes; deletion of SET1 restores both viability and APT recruitment in swd2Δ cells, revealing that Pta1-containing APT complex function is antagonized by COMPASS. Genetic epistasis (double deletion analysis), chromatin immunoprecipitation, gene expression analysis The Journal of biological chemistry Medium 22431730
2019 SYMPK (symplekin) is highly expressed in mouse embryonic stem cells (ESCs) and promotes ESC self-renewal and pluripotency. SYMPK interacts with the pluripotency factor Oct4 via its DUF3453 domain; deletion of this domain impairs colony formation. SYMPK overexpression activates proliferation-related genes and suppresses differentiation-related genes, while CRISPR/Cas9-mediated deletion decreases colony formation. CRISPR/Cas9 knockout, overexpression, co-immunoprecipitation (SYMPK-Oct4 interaction), domain deletion analysis (DUF3453), teratoma formation, chimeric mouse generation, RNA-seq Stem cells (Dayton, Ohio) Medium 30801858
2021 SYMPK is required for male germ cell development and meiosis in mice. Germ cell-specific knockout of Sympk leads to male infertility; early knockout (Ddx4-cre) results in loss of spermatogonia, while later knockout (Stra8-cre) causes defects in homologous chromosome synapsis, DNA double-strand break repair, and meiotic recombination. RNA-seq reveals SYMPK regulates alternative splicing in spermatogenic cells, and its deletion causes abnormal alternative splicing and decreased expression of Sun1 (a meiotic chromosome tether). Conditional knockout mice (two Cre lines), histology, chromosome spreads, γH2AX/SYCP3 immunostaining for DSB repair and synapsis, RNA-seq for gene expression and alternative splicing analysis Frontiers in cell and developmental biology High 34434935
2026 SYMPK dynamically localizes to spindle microtubules during oocyte meiotic maturation following germinal vesicle breakdown. Oocyte-specific knockout of Sympk causes complete female infertility with predominant metaphase I arrest, disorganized spindle architecture, and destabilized kinetochore-microtubule attachments. Pharmacologic SAC (spindle assembly checkpoint) inhibition partially restores meiotic progression but not spindle integrity. By immunoprecipitation-mass spectrometry, SYMPK interacts with spindle regulators KIF20A and NUMA1, and is required for their proper spindle localization. Oocyte-specific conditional knockout mice, live imaging of spindle dynamics, chromosome spreads, immunoprecipitation-mass spectrometry (IP-MS), SAC pharmacologic inhibition, immunofluorescence for KIF20A and NUMA1 localization Journal of genetics and genomics High 41520922

Source papers

Stage 0 corpus · 113 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2001 The sequence of the human genome. Science (New York, N.Y.) 8428 11181995
2002 Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences. Proceedings of the National Academy of Sciences of the United States of America 1479 12477932
2004 Large-scale characterization of HeLa cell nuclear phosphoproteins. Proceedings of the National Academy of Sciences of the United States of America 1159 15302935
2015 The BioPlex Network: A Systematic Exploration of the Human Interactome. Cell 1118 26186194
2017 Architecture of the human interactome defines protein communities and disease networks. Nature 1085 28514442
2015 A human interactome in three quantitative dimensions organized by stoichiometries and abundances. Cell 1015 26496610
2018 VIRMA mediates preferential m6A mRNA methylation in 3'UTR and near stop codon and associates with alternative polyadenylation. Cell discovery 829 29507755
2021 Dual proteome-scale networks reveal cell-specific remodeling of the human interactome. Cell 705 33961781
2011 Phylogenetic-based propagation of functional annotations within the Gene Ontology consortium. Briefings in bioinformatics 656 21873635
2008 The MC-Fold and MC-Sym pipeline infers RNA structure from sequence data. Nature 618 18322526
2018 High-Density Proximity Mapping Reveals the Subcellular Organization of mRNA-Associated Granules and Bodies. Molecular cell 580 29395067
1987 Promoters in the nodulation region of the Rhizobium leguminosarum Sym plasmid pRL1JI. Plant molecular biology 572 24276795
2021 Multilevel proteomics reveals host perturbations by SARS-CoV-2 and SARS-CoV. Nature 532 33845483
2004 The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome research 438 15489334
2022 OpenCell: Endogenous tagging for the cartography of human cellular organization. Science (New York, N.Y.) 432 35271311
2005 Diversification of transcriptional modulation: large-scale identification and characterization of putative alternative promoters of human genes. Genome research 409 16344560
2015 Panorama of ancient metazoan macromolecular complexes. Nature 407 26344197
2021 A proximity-dependent biotinylation map of a human cell. Nature 339 34079125
1998 Huntingtin interacts with a family of WW domain proteins. Human molecular genetics 338 9700202
2004 Symplekin and xGLD-2 are required for CPEB-mediated cytoplasmic polyadenylation. Cell 272 15550246
2011 A function for cyclin D1 in DNA repair uncovered by protein interactome analyses in human cancers. Nature 269 21654808
2017 A Compendium of RNA-Binding Proteins that Regulate MicroRNA Biogenesis. Molecular cell 248 28431233
1996 Symplekin, a novel type of tight junction plaque protein. The Journal of cell biology 248 8769423
2013 SyM-BBB: a microfluidic Blood Brain Barrier model. Lab on a chip 243 23344641
2008 A PtdIns4,5P2-regulated nuclear poly(A) polymerase controls expression of select mRNAs. Nature 225 18288197
2013 PRP19 transforms into a sensor of RPA-ssDNA after DNA damage and drives ATR activation via a ubiquitin-mediated circuitry. Molecular cell 204 24332808
2000 Complex protein interactions within the human polyadenylation machinery identify a novel component. Molecular and cellular biology 200 10669729
2005 WW domains provide a platform for the assembly of multiprotein networks. Molecular and cellular biology 184 16055720
2017 The E3 ubiquitin ligase and RNA-binding protein ZNF598 orchestrates ribosome quality control of premature polyadenylated mRNAs. Nature communications 176 28685749
2019 H4K20me0 recognition by BRCA1-BARD1 directs homologous recombination to sister chromatids. Nature cell biology 162 30804502
2020 Synthetic Lethal and Resistance Interactions with BET Bromodomain Inhibitors in Triple-Negative Breast Cancer. Molecular cell 159 32416067
2011 Maintenance of silent chromatin through replication requires SWI/SNF-like chromatin remodeler SMARCAD1. Molecular cell 148 21549307
2012 Functional proteomics establishes the interaction of SIRT7 with chromatin remodeling complexes and expands its role in regulation of RNA polymerase I transcription. Molecular & cellular proteomics : MCP 145 22586326
2000 Poliovirus RNA-dependent RNA polymerase (3D(pol)). Assembly of stable, elongation-competent complexes by using a symmetrical primer-template substrate (sym/sub). The Journal of biological chemistry 124 10681506
2002 Rice SPK, a calmodulin-like domain protein kinase, is required for storage product accumulation during seed development: phosphorylation of sucrose synthase is a possible factor. The Plant cell 118 11910009
1993 Molecular cloning and characterization of a sym plasmid locus that regulates cultivar-specific nodulation of soybean by Rhizobium fredii USDA257. Molecular microbiology 99 8412662
1987 Induction of the nodA promoter of Rhizobium leguminosarum Sym plasmid pRL1JI by plant flavanones and flavones. Journal of bacteriology 94 3539915
1997 (2S,4R)-4-methylglutamic acid (SYM 2081): a selective, high-affinity ligand for kainate receptors. The Journal of pharmacology and experimental therapeutics 93 8996224
1999 Pta1, a component of yeast CF II, is required for both cleavage and poly(A) addition of mRNA precursor. Molecular and cellular biology 81 10523662
2008 Divergence of evolutionary ways among common sym genes: CASTOR and CCaMK show functional conservation between two symbiosis systems and constitute the root of a common signaling pathway. Plant & cell physiology 74 18852152
1987 Genes for the catabolism and synthesis of an opine-like compound in Rhizobium meliloti are closely linked and on the Sym plasmid. Proceedings of the National Academy of Sciences of the United States of America 66 16593802
2004 The LFA-1-associated molecule PTA-1 (CD226) on T cells forms a dynamic molecular complex with protein 4.1G and human discs large. The Journal of biological chemistry 59 15138281
1998 The methylglutamate, SYM 2081, is a potent and highly selective agonist at kainate receptors. The Journal of pharmacology and experimental therapeutics 53 9580595
2001 The complete nucleotide sequence of a plant root-inducing (Ri) plasmid indicates its chimeric structure and evolutionary relationship between tumor-inducing (Ti) and symbiotic (Sym) plasmids in Rhizobiaceae. Journal of molecular biology 52 11273700
2009 The essential N terminus of the Pta1 scaffold protein is required for snoRNA transcription termination and Ssu72 function but is dispensable for pre-mRNA 3'-end processing. Molecular and cellular biology 50 19188448
2021 The rice LEC1-like transcription factor OsNF-YB9 interacts with SPK, an endosperm-specific sucrose synthase protein kinase, and functions in seed development. The Plant journal : for cell and molecular biology 48 33721364
2010 Evolution and multifarious horizontal transfer of an alternative biosynthetic pathway for the alternative polyamine sym-homospermidine. The Journal of biological chemistry 47 20194510
1989 nodO, a new nod gene of the Rhizobium leguminosarum biovar viciae sym plasmid pRL1JI, encodes a secreted protein. Journal of bacteriology 45 2687250
1983 Sym plasmid transfer to various symbiotic mutants of Rhizobium trifolii, R. leguminosarum, and R. meliloti. Journal of bacteriology 44 6315675
1999 Functional overlap between the mec-8 gene and five sym genes in Caenorhabditis elegans. Genetics 42 10471705
2012 Yeast Swd2 is essential because of antagonism between Set1 histone methyltransferase complex and APT (associated with Pta1) termination factor. The Journal of biological chemistry 41 22431730
1997 Sequential functioning of Sym-13 and Sym-31, two genes affecting symbiosome development in root nodules of pea (Pisum sativum L.). Molecular & general genetics : MGG 36 9197420
1992 PTA1, an essential gene of Saccharomyces cerevisiae affecting pre-tRNA processing. Molecular and cellular biology 35 1508188
2000 SYM-2081 a kainate receptor antagonist reduces allodynia and hyperalgesia in a freeze injury model of neuropathic pain. Brain research 33 10700603
2000 SPK-1, a C. elegans SR protein kinase homologue, is essential for embryogenesis and required for germline development. Mechanisms of development 33 11091073
1989 Additional nodulation genes on the Sym plasmid of Rhizobium leguminosarum biovar viciae. Plant molecular biology 32 2562395
1997 TLiSA1 (PTA1) activation antigen implicated in T cell differentiation and platelet activation is a member of the immunoglobulin superfamily exhibiting distinctive regulation of expression. The Journal of biological chemistry 31 9268302
1997 A Rhizobium leguminosarum biovar trifolii locus not localized on the sym plasmid hinders effective nodulation on plants of the pea cross-inoculation group. Molecular plant-microbe interactions : MPMI 31 9304865
1990 sym 13-A Gene Conditioning Ineffective Nodulation in Pisum sativum. Plant physiology 30 16667870
1989 Transcription of rhiA, a gene on a Rhizobium leguminosarum bv. viciae Sym plasmid, requires rhiR and is repressed by flavanoids that induce nod genes. Molecular microbiology 25 2716520
1992 Transconjugants of Agrobacterium radiobacter harbouring sym genes of Rhizobium galegae can form an effective symbiosis with Medicago sativa. FEMS microbiology letters 24 1499987
1991 Light Microscopy Study of Nodule Initiation in Pisum sativum L. cv Sparkle and in Its Low-Nodulating Mutant E2 (sym 5). Plant physiology 22 16668510
1988 Hepatocyte initiation during continuous administration of diethylnitrosamine and 1,2-sym-dimethylhydrazine. Cancer research 22 2892585
2005 Efficacy and safety of tacrolimus compared with cyclosporin microemulsion in primary SPK transplantation: 3-year results of the Euro-SPK 001 trial. Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association 21 15814547
2011 NMR structure of a 4 x 4 nucleotide RNA internal loop from an R2 retrotransposon: identification of a three purine-purine sheared pair motif and comparison to MC-SYM predictions. RNA (New York, N.Y.) 20 21778280
2009 Identification and characterization of a matrix metalloproteinase (Pta1-MMP) expressed during Loblolly pine (Pinus taeda) seed development, germination completion, and early seedling establishment. Planta 19 19466448
2004 The identities of sym-2, sym-3 and sym-4, three genes that are synthetically lethal with mec-8 in Caenorhabditis elegans. Genetics 19 15579686
1999 RNA maturation of the rice SPK gene may involve trans-splicing. The Plant journal : for cell and molecular biology 19 10417713
1988 Detection and subcellular localization of two Sym plasmid-dependent proteins of Rhizobium leguminosarum biovar viciae. Journal of bacteriology 18 3410833
1985 Expression of a Rhizobium phaseoli Sym plasmid in R. trifolii and Agrobacterium tumefaciens: incompatibility with a R. trifolii Sym plasmid. Plasmid 18 2994130
1979 The use of sym-triazine trichloride in RNA-protein cross-linking studies with Escherichia coli ribosomal subunits. Molecular & general genetics : MGG 18 372742
2011 Treatment of fish parasites: 5. The effects of sym. triazinone (Toltrazuril) on fish parasitic ciliophora (Ichthyophthirius multifiliis FOUQUET, 1876, Apiosoma amoebea GRENFELL, 1884, Trichodina sp. EHRENBERG, 1831). European journal of protistology 15 23195567
2000 Preparation and characterization of mabs against different epitopes of CD226 (PTA1). Hybridoma 15 11152401
1989 Localization and symbiotic function of a region on the Rhizobium leguminosarum Sym plasmid pRL1JI responsible for a secreted, flavonoid-inducible 50-kilodalton protein. Journal of bacteriology 15 2644226
2013 Biological activity of sym-triazines with acetylcholine-like substitutions as multitarget modulators of Alzheimer's disease. ACS chemical neuroscience 14 23472585
2004 A rice antisense SPK transformant that lacks the accumulation of seed storage substances shows no correlation between sucrose concentration in phloem sap and demand for carbon sources in the sink organs. Plant & cell physiology 13 15356337
2011 SPK-1, an SR protein kinase, inhibits programmed cell death in Caenorhabditis elegans. Proceedings of the National Academy of Sciences of the United States of America 12 21245325
2009 C. elegans sym-1 is a downstream target of the hunchback-like-1 developmental timing transcription factor. Cell cycle (Georgetown, Tex.) 12 19923914
1984 Comparative studies of rabies and Sindbis virus replication in human neuroblastoma (SYM-I) cells that can produce interferon. The Journal of general virology 12 6208314
2007 Binding of the PTA1 transcriptional activator to the divergent promoter region of the first two genes of the penicillin pathway in different Penicillium species. Current genetics 10 17924108
1980 Enzymic synthesis of sym-homospermidine in Lathyrus sativus (grass pea) seedlings. The Biochemical journal 10 7470060
2021 SYMPK Is Required for Meiosis and Involved in Alternative Splicing in Male Germ Cells. Frontiers in cell and developmental biology 9 34434935
2020 Characterization of SPK 98, a Torin2 analog, as ATR and mTOR dual kinase inhibitor. Bioorganic & medicinal chemistry letters 9 32911078
2011 RNA2 of TRV SYM breaks the rules for tobravirus genome structure. Virus research 9 21798296
1997 Dimethyldioxirane converts benzene oxide/oxepin into (Z,Z)-muconaldehyde and sym-oxepin oxide: modeling the metabolism of benzene and its photooxidative degradation. Chemical research in toxicology 9 9437519
1994 Sequence and regulation of psrA, a gene on the Sym plasmid of Rhizobium leguminosarum biover phaseoli which inhibits transcription of the psi genes. Microbiology (Reading, England) 9 8012570
1992 Pleiotropic Effects of sym-17 : A Mutation in Pisum sativum L. cv Sparkle Causes Decreased Nodulation, Altered Root and Shoot Growth, and Increased Ethylene Production. Plant physiology 9 16653124
2006 Structural analysis of the plasmid pTA1 isolated from the thermoacidophilic archaeon Thermoplasma acidophilum. Extremophiles : life under extreme conditions 8 16493526
1999 Isolation of cDNAs encoding gibbon and monkey platelet and T cell activation antigen 1 (PTA1). DNA sequence : the journal of DNA sequencing and mapping 8 10647817
1985 Effect of Sym Plasmid Curing on Symbiotic Effectiveness in Rhizobium fredii. Applied and environmental microbiology 8 16346803
2009 Involvement of Pta1, Pcf11 and a KlCYC1 AU-rich element in alternative RNA 3'-end processing selection in yeast. FEBS letters 7 19646984
1991 Distribution of O-acetyl groups in the exopolysaccharide synthesized by Rhizobium leguminosarum strains is not determined by the Sym plasmid. The Journal of biological chemistry 7 2033052
2020 The pseudogene problem and RT-qPCR data normalization; SYMPK: a suitable reference gene for papillary thyroid carcinoma. Scientific reports 6 33110161
2015 A single sym plasmid type predominates across diverse chromosomal lineages of Cupriavidus nodule symbionts. Systematic and applied microbiology 6 26159623
1994 Structure and expression of Spk-1, an src-related gene product found in the planarian Dugesia (G) tigrina. Oncogene 5 7510865
1983 Reversibility of self-phosphorylation of a histidine residue of adrenocortical cyclic nucleotide-independent protein kinase, SPK 380. Biochemical and biophysical research communications 5 6847686
2025 The IAA-Producing Rhizobacterium Bacillus sp. SYM-4 Promotes Maize Growth and Yield. Plants (Basel, Switzerland) 4 40508264
2015 Amino acids in sandal (Santalum album L) with special reference to cis-4-hydroxy-l-proline and sym. homospermidine. SpringerPlus 4 26435892
2023 Impacts of Natural Selection on Evolution of Core and Symbiotically Specialized (sym) Genes in the Polytypic Species Neorhizobium galegae. International journal of molecular sciences 3 38069024
2019 Interaction Between Sympk and Oct4 Promotes Mouse Embryonic Stem Cell Proliferation. Stem cells (Dayton, Ohio) 3 30801858
2007 Generation of rat monoclonal antibodies against murine PTA1/CD226. Hybridoma (2005) 3 17451354
1988 Characterization of Sym plasmids of Rhizobium leguminosarum strains able to nodulate Pisum sativum cv Afghanistan. Plant molecular biology 3 24272399
1985 Inhibition of the activities of DNA primase-polymerase alpha complex from KB cells by hexasodium sym-bis(m-aminobenzoyl-m-amino-p-methylbenzoyl-1-naphthylamino-4 ,6,8-trisulfonate)carbamide. Nucleic acids symposium series 3 4088877
2021 sym-2 loss-of-function causes glutamatergic neurodegeneration after oxidative stress. microPublication biology 2 33554054
1998 [PTA1 monoclonal antibody induces human platelet aggregation and intra-cytoplasmic Ca2+ elevation]. Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 2 11243144
1990 An altered constitutive peptide in sym 5 mutants of Pisum sativum L. Plant molecular biology 2 1714314
2008 The function of three indigenous plasmids in Mesorhizobium huakuii 2020 and its symbiotic interaction with Sym pJB5JI of Rhizobium leguminosarum. Science in China. Series C, Life sciences 1 18368313
2026 SYMPK interacts with KIF20A and NUMA1 to coordinate spindle organization and safeguard oocyte meiotic maturation. Journal of genetics and genomics = Yi chuan xue bao 0 41520922
2025 A non-canonical fungal peroxisome PTS-1 signal, SYM, and its evolutionary aspects. Scientific reports 0 40750654
2023 A new metabolic pathway for sym-homospermidine synthesis in an extreme thermophile, Thermus thermophilus. The Journal of general and applied microbiology 0 37532583
2017 [Roles of SPK in Regulation of Hypoxia Induced Proliferation and Glucose Consume of Leukemia Cells]. Zhongguo shi yan xue ye xue za zhi 0 28823252
2005 [The influence of platelets on PTA1 expression and PDGF release from ECV304 cells]. Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 0 16143072
2000 [Ligand of platelet and T cell activation antigen 1 (PTA1) expressed on Colo205 cell surface]. Zhonghua zhong liu za zhi [Chinese journal of oncology] 0 11778269