Affinage

GORASP1

Golgi reassembly-stacking protein 1 · UniProt Q9BQQ3

Length
440 aa
Mass
46.5 kDa
Annotated
2026-06-10
38 papers in source corpus 30 papers cited in narrative 30 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 8/8 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

GORASP1 (GRASP65) is a peripheral cis-Golgi membrane protein that physically tethers and stacks Golgi cisternae and is integrated into mitotic cell-cycle control of Golgi architecture (PMID:9346242, PMID:12839990). Its N-terminal GRASP domain (PDZ1/PDZ2) is necessary and sufficient for dimerization and trans-oligomerization, the activity that holds adjacent cisternae together (PMID:15576368, PMID:20214750), with a crystallographically defined dimer in which one GRASP domain's C-terminal tail inserts into the PDZ1 pocket of an adjacent dimer—two individually weak contacts that together drive stacking (PMID:23940043). Through these PDZ domains GRASP65 constitutively binds the C-terminal tail of GM130 at two concurrent sites engaging both PDZ1 and PDZ2, an interaction required for correct Golgi targeting of both proteins and for vesicle tethering (PMID:9628863, PMID:26363069). GRASP65 together with GM130 mediates lateral cisternal fusion to build the Golgi ribbon and ensure uniform glycosylation enzyme distribution (PMID:16489344), and it acts redundantly with GRASP55: loss of both, but not either alone, disperses the stack and impairs accurate protein and lipid glycosylation (PMID:20083603, PMID:28814501). Oligomerization is dissolved during mitosis by sequential C-terminal phosphorylation: Cdk1-cyclin B phosphorylates multiple consensus sites and recruits the Plk1 polo-box domain, while PLK1 also acts at an N-terminal site adjacent to an internal PDZ ligand to disrupt self-interaction and unlink the ribbon (PMID:15678101, PMID:20937827, PMID:23259055); an ERK/JNK2-targeted Ser277/S274 site, downstream of a PKD2 signaling axis, drives interphase and G2 unstacking that governs Golgi orientation during migration and timely mitotic entry (PMID:15834132, PMID:18762583, PMID:25948586, PMID:41892354). During apoptosis caspase-3 cleaves the C-terminus, releasing mitochondria-targeted fragments that promote cell death (PMID:11815631, PMID:21368855). GRASP65 additionally facilitates PDZ-dependent transport of C-terminal valine-bearing cargoes (PMID:19840934) and stabilizes newly nucleated microtubules (PMID:31336000). Human loss-of-function (p.Asp390Glufs*18, absent protein) causes a neurodevelopmental Golgipathy characterized by hyposialylation and mitotic delay without Golgi fragmentation (PMID:39933924).

Mechanistic history

Synthesis pass · year-by-year structured walk · 30 steps
  1. 1997 High

    Established GRASP65 as a Golgi membrane protein with direct stacking activity, answering whether a defined factor controls cisternal stacking.

    Evidence Cell-free cisternal stacking assay with antibody/recombinant inhibition and co-IP with GM130

    PMID:9346242

    Open questions at the time
    • Molecular basis of stacking activity not yet resolved
    • Phosphoregulation defined only as bulk mitotic phosphorylation
  2. 1998 High

    Mapped the reciprocal GRASP65-GM130 binding sites and showed the interaction targets both proteins to the Golgi, defining the first molecular partner contact.

    Evidence Gel filtration, in vitro translation, site-directed mutagenesis, GFP-reporter targeting

    PMID:9628863

    Open questions at the time
    • Single-site model later revised by structural work
    • Did not establish stoichiometry or affinity
  3. 2000 High

    Identified Plk and Cdc2 as the kinases acting on GRASP65, linking it to mitotic kinase cascades.

    Evidence Yeast two-hybrid, in vitro and in vivo kinase assays, Plk deletion mutants

    PMID:11050165

    Open questions at the time
    • Specific phosphosites not yet mapped
    • Functional consequence on stacking not directly tested here
  4. 2002 High

    Showed caspase-3 cleaves GRASP65 during apoptosis to drive Golgi breakdown, connecting it to programmed cell death.

    Evidence Caspase cleavage assays, caspase-resistant mutant expression, Golgi EM

    PMID:11815631

    Open questions at the time
    • Fate and function of cleavage fragments not yet defined
    • Physiological apoptotic trigger not specified
  5. 2003 High

    Demonstrated directly that mitotic kinases disaggregate GRASP65 trans-oligomers and dephosphorylation re-aggregates them, establishing phospho-regulated oligomerization as the stacking switch.

    Evidence Bead aggregation assay, cell-free Golgi disassembly/reassembly, microinjection of anti-GRASP65 antibody

    PMID:12839990

    Open questions at the time
    • Structural geometry of trans-oligomer unknown
    • Individual phosphosite contributions unresolved
  6. 2004 High

    Separated GRASP65 into an N-terminal oligomerization module and a C-terminal phosphoregulatory module, defining domain architecture.

    Evidence Domain deletion/truncation with oligomerization and Golgi fragmentation readouts

    PMID:15576368

    Open questions at the time
    • Atomic structure of GRASP domain not yet available
    • C-terminal phosphosite identities incomplete
  7. 2005 High

    Defined the Cdk1-cyclin B four-site phosphorylation that creates the Plk1 polo-box docking platform and gates mitotic entry, establishing the priming-kinase mechanism.

    Evidence In vitro kinase and polo-box binding assays, alanine mutagenesis, cell cycle progression in NRK cells

    PMID:15678101

    Open questions at the time
    • How Golgi unstacking signals back to mitotic entry not mechanistically resolved
  8. 2005 Medium

    Revealed a GRASP65 requirement for spindle integrity and cell cycle control beyond Golgi stacking.

    Evidence RNAi depletion in HeLa cells, spindle/centrosome immunofluorescence, C-terminal overexpression

    PMID:15888544

    Open questions at the time
    • Mechanism connecting GRASP65 to spindle dynamics not resolved
    • Indirect effect via Golgi-mitosis checkpoint not excluded
  9. 2005 High

    Showed Ser277 is an ERK target in interphase but a Cdk1 target in mitosis, identifying a signal-integrating phosphosite.

    Evidence In vitro kinase assays, phospho-specific antibody, microinjection of fragments, S277A mutagenesis

    PMID:15834132

    Open questions at the time
    • Downstream effector of Ser277 phosphorylation not defined here
  10. 2006 High

    Established that GM130 and GRASP65 jointly mediate lateral cisternal fusion required for ribbon formation and uniform enzyme distribution.

    Evidence RNAi knockdown, quantitative Golgi ribbon imaging, enzyme distribution assays

    PMID:16489344

    Open questions at the time
    • Fusion machinery downstream of tethering not identified
    • Glycosylation consequences not directly measured
  11. 2007 Medium

    Showed the yeast orthologue Grh1 acts at COPII-to-cis-Golgi traffic via Bug1 and Sec23/24, placing GRASP function in early secretory pathway biogenesis.

    Evidence Fractionation, reciprocal co-IP, genetic interaction analysis in yeast

    PMID:17261844

    Open questions at the time
    • Conservation of COPII-coupling role in mammalian GRASP65 not tested
    • Single-lab yeast genetics
  12. 2008 High

    Linked EGF/LPA-ERK phosphorylation of Ser277 to GRASP65 de-oligomerization and Golgi reorientation during directed cell migration, extending function to interphase polarity.

    Evidence ERK kinase assay, phospho-mutants, wound-healing migration, brefeldin A rescue

    PMID:18762583

    Open questions at the time
    • How Golgi unstacking promotes centrosome/Golgi orientation mechanistically unclear
  13. 2009 Medium

    Identified PDZ-dependent binding of C-terminal valine cargo receptors, assigning GRASP65 a direct cargo-transport role.

    Evidence Direct PDZ-cargo binding assay, RNAi depletion, trafficking assays

    PMID:19840934

    Open questions at the time
    • Generality of valine-motif cargo selection not established
    • Single-lab evidence
  14. 2010 High

    Resolved that non-regulatable GRASP65 enhances stacking and blocks mitotic fragmentation, and that Golgi disassembly is needed for timely mitotic entry, tying organelle inheritance to cell cycle.

    Evidence Domain truncation, EM, siRNA rescue, brefeldin A treatment, cell cycle assays

    PMID:20214750

    Open questions at the time
    • Checkpoint sensor reading Golgi state not identified
  15. 2010 High

    Pinpointed a PLK1 site within the N-terminal domain adjacent to an internal PDZ ligand whose phosphorylation toggles tethering versus unlinking, defining the structural switch for mitotic unstacking.

    Evidence PLK1 in vitro kinase, phospho-mimetic/alanine mutagenesis, organelle tethering assay

    PMID:20937827

    Open questions at the time
    • Crystallographic basis of the internal-ligand contact not yet shown
  16. 2010 High

    Demonstrated functional redundancy: only dual GRASP55/GRASP65 depletion collapses the entire stack, refining each GRASP's contribution.

    Evidence siRNA double knockdown, EM, phospho-mutant expression

    PMID:20083603

    Open questions at the time
    • Whether redundancy reflects identical or distinct cisternal contacts unresolved
  17. 2010 Medium

    Confirmed caspase-cleaved GRASP65 C-terminal fragments traffic to mitochondria and promote Fas-mediated apoptosis, linking Golgi disassembly to cell-death execution.

    Evidence Caspase-resistant mutants, fractionation, co-IP with Bcl-XL

    PMID:21368855

    Open questions at the time
    • Bcl-XL interaction rests on a single Co-IP without reciprocal validation
    • Pro-death mechanism of fragments not defined
  18. 2012 High

    Defined the temporal order of mitotic phosphorylation across T220/T224, S277, and S376, with T220/T224 dominant for fragmentation, building a phospho-timing map.

    Evidence Phospho-specific antibodies, in vitro kinase assays, phospho-resistant mutants, immunofluorescence

    PMID:23259055

    Open questions at the time
    • Phosphatases controlling dephosphorylation timing not identified
  19. 2013 High

    Provided the atomic GRASP-domain dimer structure showing the PDZ2-PDZ2 plus PDZ1-tail-insertion contacts that mediate stacking, explaining the trans-oligomer geometry.

    Evidence X-ray crystallography of GRASP domain, binding assays, mutagenesis

    PMID:23940043

    Open questions at the time
    • Higher-order oligomer assembly on membranes not directly visualized
  20. 2014 High

    Showed via knockout mice that GRASP65 is dispensable for ribbon morphology and viability but required for cis-cisternal continuity and normal glycosylation, separating structural from functional roles.

    Evidence Knockout mice, FRAP, GSII lectin staining, EM

    PMID:24795147

    Open questions at the time
    • Compensation by GRASP55 in vivo not quantified
    • Tissue-specific phenotypes not detailed
  21. 2015 High

    Identified JNK2 as the G2 kinase phosphorylating Ser277 to unlink the ribbon and license mitotic entry, with FRAP showing tubule severing.

    Evidence JNK2 RNAi, JNK inhibitors, FRAP, brefeldin A rescue, cell cycle analysis

    PMID:25948586

    Open questions at the time
    • Upstream activator of JNK2 at the Golgi not identified here
  22. 2015 High

    Revised the GRASP65-GM130 model structurally, showing GM130 engages both PDZ1 and PDZ2 simultaneously, correcting a PDZ2-only view.

    Evidence 1.96 Å crystal structure, mutagenesis, co-IP

    PMID:26363069

    Open questions at the time
    • How GM130 binding coexists with stacking trans-interactions on the same domains unresolved
  23. 2015 Medium

    Connected GRASP65 to the actin cytoskeleton via Mena, with actin promoting GRASP65 oligomerization and Golgi fusion.

    Evidence Co-IP, recruitment assay, siRNA, in vitro Golgi fusion

    PMID:26538023

    Open questions at the time
    • Mechanism by which actin enhances oligomerization unresolved
    • Single-lab evidence
  24. 2016 Medium

    Showed HCMV exploits GRASP65 phosphorylation-dependent ribbon fragmentation for virion assembly, linking the unstacking pathway to viral pathogenesis.

    Evidence Pharmacological inhibition, infectious yield, virion protein incorporation

    PMID:27703074

    Open questions at the time
    • Viral kinase/effector driving GRASP65 phosphorylation not identified
    • Pharmacological specificity limits mechanism
  25. 2017 High

    CRISPR double knockout confirmed GRASP55/GRASP65 are required for stacking, controlled trafficking rate, and accurate glycosylation, consolidating the redundancy model with genetic rigor.

    Evidence CRISPR/Cas9 knockout, EM, trafficking and glycosylation assays

    PMID:28814501

    Open questions at the time
    • Direct molecular link between stacking and glycosylation fidelity not defined
  26. 2018 High

    Identified DjA1 as a direct GRASP65 partner that promotes oligomerization independent of Hsc70 cochaperone activity, adding a positive regulator of stacking.

    Evidence Co-IP, siRNA, in vitro fusion, immunodepletion, purified-protein reconstitution

    PMID:30566031

    Open questions at the time
    • How DjA1 structurally promotes oligomerization unresolved
  27. 2019 Medium

    Assigned GRASP65 a role in stabilizing newly nucleated microtubules and Golgi clustering under JNK/ERK phospho-control of S274, broadening function to the cytoskeleton.

    Evidence RNAi, microtubule regrowth assay, tubulin acetylation IF, phospho-mutants

    PMID:31336000

    Open questions at the time
    • Direct versus indirect microtubule stabilization mechanism unclear
    • Single-lab evidence
  28. 2021 High

    Acute degron depletion showed neither GRASP alone nor both are strictly required to maintain or rebuild stacks, but dual loss strips GM130/p115/Golgin-45 and impairs ribbon linking, refining GRASP65's role toward tethering-protein retention.

    Evidence Degron-tag rapid degradation, EM, tethering-protein immunofluorescence

    PMID:33301566

    Open questions at the time
    • Reconciliation with prior siRNA stacking phenotypes incomplete
    • What sustains stacking in GRASP absence unknown
  29. 2025 High

    Established a human Mendelian disease link: GORASP1 loss-of-function causes a neurodevelopmental Golgipathy with hyposialylation and mitotic delay, validating the gene's physiological glycosylation and cell-cycle functions in humans.

    Evidence Patient variant, CRISPR recapitulation in RPE cells, glycosylation and mitosis analysis

    PMID:39933924

    Open questions at the time
    • Mechanistic basis of mitotic delay in patient cells not fully resolved
    • Genotype-phenotype range from single family
  30. 2026 Medium

    Placed PKD2 upstream of GRASP65 S274 phosphorylation and ribbon unlinking, identifying an additional kinase input to the G2/M Golgi switch.

    Evidence Phospho-specific antibody, PKD2 inhibitor and siRNA, Golgi structure and cell cycle assays

    PMID:41892354

    Open questions at the time
    • Whether PKD2 acts directly or via JNK2/ERK not resolved
    • Single-lab, single-paper evidence

Open questions

Synthesis pass · forward-looking unresolved questions
  • How the structural stacking activity of GRASP65 mechanistically governs glycosylation fidelity and mitotic timing—and how its many kinase inputs are integrated—remains unresolved.
  • No unified model linking cisternal continuity to glycosylation accuracy
  • Checkpoint sensor coupling Golgi state to mitotic entry unidentified
  • Hierarchy among Cdk1, Plk1, ERK, JNK2, and PKD2 inputs not established

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 4 GO:0005198 structural molecule activity 3 GO:0008092 cytoskeletal protein binding 2
Localization
GO:0005794 Golgi apparatus 4 GO:0005739 mitochondrion 2
Pathway
R-HSA-1640170 Cell Cycle 4 R-HSA-1852241 Organelle biogenesis and maintenance 3 R-HSA-9609507 Protein localization 3 R-HSA-5357801 Programmed Cell Death 2
Partners
CDK1DNAJA1ENAHERKGM130JNK2PKD2PLK1

Evidence

Reading pass · 30 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1997 GRASP65 is a 65 kDa Golgi membrane protein whose antibodies and recombinant form block cisternal stacking in a cell-free system; it forms a complex with GM130 and is tightly bound to Golgi membranes even under mitotic conditions when both proteins are heavily phosphorylated, linking it to vesicle docking and cisternal stacking. Cell-free cisternal stacking assay, antibody inhibition, co-immunoprecipitation, biochemical fractionation Cell High 9346242
1998 The binding site for GRASP65 on GM130 maps to the C-terminal sequence xxNDxxxIMVI of GM130, while the binding site for GM130 on GRASP65 maps to amino acids 189–201 (reminiscent of PDZ domains); interaction of the two proteins is required for correct targeting of both to the Golgi apparatus. Gel filtration, in vitro translation, site-directed mutagenesis, immunoprecipitation, GFP-reporter targeting assays The EMBO journal High 9628863
2000 Polo-like kinase (Plk) binds GRASP65 (identified by yeast two-hybrid) and phosphorylates it both in vitro and in vivo; Cdc2 also phosphorylates GRASP65; the conserved C-terminal domain of Plk is required for efficient GRASP65 phosphorylation. Yeast two-hybrid, in vitro kinase assay, in vivo phosphorylation, deletion/frameshift mutant analysis Proceedings of the National Academy of Sciences of the United States of America High 11050165
2002 GRASP65 is cleaved specifically by caspase-3 at conserved sites in its C-terminus during apoptosis; expression of a caspase-resistant GRASP65 partially preserved cisternal stacking and inhibited Golgi ribbon breakdown in apoptotic cells. Caspase cleavage assay, expression of caspase-resistant mutants, electron microscopy of Golgi ultrastructure The Journal of cell biology High 11815631
2003 GRASP65 is the major phosphorylation target of cdc2-cyclin B and polo-like kinases in rat liver Golgi membranes; these kinases alone can unstack Golgi membranes; GRASP65 homodimers on beads form trans-oligomeric aggregates that are disaggregated by mitotic kinases and re-aggregated after dephosphorylation, demonstrating direct mitotically regulated stacking activity. In vitro kinase assay, cell-free Golgi disassembly/reassembly assay, bead aggregation assay, microinjection of anti-GRASP65 antibodies The EMBO journal High 12839990
2004 The N-terminal GRASP domain (aa 1–201) of GRASP65 is necessary and sufficient for dimerization and trans-oligomerization; the C-terminal serine/proline-rich domain (aa 202–446) confers mitotic regulation through phosphorylation sites targeted by cdc2/cyclin B1 and polo-like kinase. Domain deletion/truncation expression, biochemical oligomerization assays, transient overexpression with Golgi fragmentation readout The Journal of biological chemistry High 15576368
2005 Cdk1-cyclin B phosphorylates GRASP65 at four C-terminal consensus sites, and phosphorylated GRASP65 recruits the polo box domain of Plk1; mutation of these four sites to alanine abolishes mitotic phosphorylation and Plk1 binding; expression of wild-type but not phosphorylation-defective GRASP65 C-terminus delays mitotic entry. In vitro kinase assay, polo-box domain binding assay, alanine mutagenesis, cell cycle progression assay in NRK cells The EMBO journal High 15678101
2005 GRASP65 depletion by RNAi causes metaphase arrest with multiple aberrant spindles; the C-terminus of GRASP65 expressed in cells interferes with mitotic entry, revealing a role for GRASP65 in spindle dynamics and cell cycle control beyond Golgi stacking. RNAi depletion in HeLa cells, immunofluorescence microscopy of spindle/centrosome markers, C-terminal construct overexpression Molecular biology of the cell Medium 15888544
2005 GRASP65 is phosphorylated at serine 277 in interphase cells in response to serum/EGF directly by ERK; during mitosis Ser-277 is phosphorylated by Cdk1 instead of ERK; microinjection of a GRASP65 fragment containing Ser-277 inhibits mitosis passage, an effect abolished by S277A mutation. In vitro kinase assay, phospho-specific antibody, microinjection of recombinant protein/peptide fragments, alanine mutagenesis The Journal of biological chemistry High 15834132
2006 Golgi ribbon formation (lateral cisternal fusion) requires both GM130 and GRASP65; these GM130- and GRASP65-dependent fusion events are necessary for uniform enzyme distribution across the Golgi ribbon. RNAi knockdown, quantitative fluorescence microscopy of Golgi ribbon, enzyme distribution assays Nature cell biology High 16489344
2007 The yeast GRASP65 orthologue Grh1 associates with the cis-Golgi via an N-terminal amphipathic helix that is N-terminally acetylated; Grh1 forms a complex with the coiled-coil protein Bug1 (Ydl099w); Grh1 interacts with the COPII coat component Sec23/24; genetic interactions with Uso1 and Ypt1 suggest the Grh1-Bug1 complex contributes to COPII vesicle consumption and cis-Golgi formation. Biochemical fractionation, co-immunoprecipitation, genetic interaction analysis, functional assays The Journal of cell biology Medium 17261844
2008 EGF or LPA stimulation activates ERK, which phosphorylates GRASP65 at serine 277; a S277A or 1–201 truncation mutant (non-phosphorylatable by ERK) prevents Golgi orientation to the leading edge and inhibits centrosome orientation during directed cell migration; ERK phosphorylation of GRASP65 causes loss of GRASP65 oligomerization and Golgi cisternal unstacking. In vitro ERK kinase assay, phospho-specific antibody, expression of phospho-mutants, wound-healing migration assay, brefeldin A rescue The Journal of cell biology High 18762583
2009 GRASP65 PDZ domains directly bind C-terminal valine-bearing cargo receptors (CD8α and Frizzled4); both GRASP65 and GRASP55 are needed sequentially for efficient transport of these receptors to and through the Golgi complex. Direct binding assay (PDZ-cargo interaction), RNAi depletion, protein trafficking assays The Journal of biological chemistry Medium 19840934
2010 The first 112 amino acids of GRASP65 (including PDZ1) are sufficient for oligomerization; expression of non-regulatable GRASP65 mutants enhances Golgi stacking in interphase and inhibits fragmentation during mitosis; GRASP65 siRNA reduces cisternae per stack and is rescued by exogenous GRASP65; inhibiting mitotic Golgi disassembly with non-regulatable GRASP65 delayed mitotic entry and suppressed cell growth, an effect rescued by brefeldin A-induced Golgi dispersal. Domain truncation analysis, electron microscopy of Golgi ultrastructure, siRNA depletion with rescue, brefeldin A treatment, cell cycle assays Traffic (Copenhagen, Denmark) High 20214750
2010 GRASP65 links cis-Golgi cisternae via a homotypic N-terminal PDZ interaction; PLK1 phosphorylates a site within the GRASP65 N-terminal domain proximate to an internal PDZ ligand; phospho-mimetic mutation at this site blocks organelle tethering, while alanine substitution prevents mitotic Golgi unlinking; an internal PDZ ligand adjacent to the PLK1 site is required for GRASP65 self-interaction. In vitro PLK1 kinase assay, phospho-mimetic and alanine mutagenesis, organelle tethering assay, interaction assays The Journal of biological chemistry High 20937827
2010 Simultaneous siRNA knockdown of both GRASP55 and GRASP65 leads to disassembly of the entire Golgi stack, whereas depletion of either alone only reduces the number of cisternae per stack; GRASP65 stacks membranes via oligomerization of its N-terminal GRASP domain, regulated by C-terminal phosphorylation. siRNA double knockdown, electron microscopy, phospho-mutant expression The Journal of cell biology High 20083603
2010 Caspase-3 cleavage of GRASP65 during Fas/CD95-mediated apoptosis is required for apoptotic progression; C-terminal caspase-cleavage fragments of GRASP65 are targeted to mitochondria and sensitize cells to Fas ligand; Bcl-XL was identified as a candidate apoptotic binding partner for GRASP65 C-terminal fragments. Caspase-resistant mutant expression, caspase cleavage assays, subcellular fractionation/localization, co-immunoprecipitation with Bcl-XL Cell death & disease Medium 21368855
2012 GRASP65 is sequentially phosphorylated during mitosis: cdc2 phosphorylates T220/T224, S277, and S376; Plk1 enhances these phosphorylations. T220/T224 is phosphorylated from prophase through anaphase; S277 and S376 from late G2 through telophase; T220A/T224A mutation inhibits mitotic Golgi fragmentation more strongly than S277A or S376A mutations; T220/224 dephosphorylation in cytokinesis precedes S277 but follows S376 dephosphorylation. Phospho-specific antibody generation, in vitro kinase assay, phospho-resistant mutant expression, immunofluorescence microscopy Biology open High 23259055
2013 Crystal structure of the GRASP65 GRASP domain reveals a dimer in which PDZ2 binding pockets face each other, with the C-terminal tail of one GRASP domain inserting into the PDZ1 pocket of another dimer; both contacts are individually weak but are required in combination for GRASP-mediated Golgi stacking. X-ray crystallography (GRASP65 GRASP domain structure), biochemical binding assays, mutagenesis The Journal of biological chemistry High 23940043
2014 In GRASP65 knockout mice, the Golgi ribbon appears morphologically normal, but FRAP reveals functional discontinuities in the cis-cisternal membrane network; loss of GRASP65 causes changes in plasma membrane glycosylation (GSII lectin staining) in tissues, demonstrating GRASP65 is required for cis-Golgi network continuity and proper glycosylation but is not essential for organism viability. Homologous recombination knockout, FRAP, GSII lectin staining, electron microscopy Biology open High 24795147
2015 JNK2 phosphorylates GRASP65 at Ser277 during G2, which is essential for separation of Golgi stacks and ribbon unlinking required for mitotic entry; JNK inhibition or JNK2 RNAi causes G2 cell cycle block; this block is bypassed by brefeldin A-induced Golgi dispersal or GRASP65 depletion; JNK2 is required for cleavage of tubules connecting Golgi stacks as measured by FRAP. RNAi knockdown of JNK2, JNK inhibitors, FRAP, brefeldin A rescue, cell cycle analysis Journal of cell science High 25948586
2015 Crystal structure of GRASP65 PDZ domains in complex with the GM130 C-terminal peptide (1.96 Å) shows that GM130 binds GRASP65 at two distinct sites concurrently, engaging both PDZ1 and PDZ2 domains (contradicting prior models of PDZ2-only interaction); mutagenesis confirms both contacts are required for GRASP65-GM130 association. X-ray crystallography, site-directed mutagenesis, co-immunoprecipitation The Journal of biological chemistry High 26363069
2015 The actin elongation factor Mena is a GRASP65-binding protein identified by biochemical methods; Mena is recruited to Golgi membranes through interaction with GRASP65; depletion of Mena or disruption of actin polymerization causes Golgi fragmentation; in vitro, Mena and microfilaments enhance GRASP65 oligomerization and Golgi membrane fusion. Co-immunoprecipitation, Golgi membrane recruitment assay, siRNA depletion, in vitro Golgi fusion assay Molecular biology of the cell Medium 26538023
2016 HCMV-induced Golgi ribbon fragmentation during virion assembly compartment formation is dependent on phosphorylation of GRASP65; inhibition of Golgi membrane fragmentation reduces infectious particle production and alters virion envelope protein incorporation. Pharmacological inhibition of GRASP65 phosphorylation, infectious virus yield assay, virion protein incorporation analysis mBio Medium 27703074
2017 CRISPR/Cas9 double knockout of GRASP55 and GRASP65 in HeLa and HEK293 cells disperses the Golgi stack into single cisternae and tubulovesicular structures, accelerates protein trafficking, and impairs accurate glycosylation of proteins and lipids. CRISPR/Cas9 knockout, electron microscopy, protein trafficking assays, glycosylation analysis Molecular biology of the cell High 28814501
2018 DjA1 (DnaJ homolog subfamily A member 1) is a GRASP65-binding protein; depletion of DjA1 causes Golgi fragmentation and delayed Golgi reassembly; immunodepletion of DjA1 from interphase cytosol reduces GRASP65 oligomerization and Golgi membrane fusion in vitro; DjA1 promotes GRASP65 oligomerization through direct interaction independent of its Hsc70 cochaperone activity. Co-immunoprecipitation, siRNA depletion, in vitro Golgi fusion assay, immunodepletion, purified protein reconstitution Molecular biology of the cell High 30566031
2019 GRASP65 is required for stabilization of newly nucleated microtubules (leading to their acetylation) and clustering of Golgi stacks; GRASP65 is not involved in microtubule nucleation or anchoring; ribbon formation and microtubule stabilization are both regulated by JNK/ERK-mediated phosphorylation of GRASP65 S274 (human); tubulin acetylation is reduced during G2 as phosphorylation of GRASP65 increases. RNAi depletion, microtubule regrowth assay, tubulin acetylation immunofluorescence, phospho-mutant expression Traffic (Copenhagen, Denmark) Medium 31336000
2021 Acute depletion of GRASP65 alone (via degron-tag) does not affect the Golgi ribbon; chronic degradation of GRASP65 does not disrupt ribbon connectivity; acute double depletion of both GRASP55 and GRASP65 causes loss of vesicle tethering proteins GM130, p115, and Golgin-45 from the Golgi and compromises ribbon linking; neither GRASP alone nor both together are required for maintaining stacks or de novo assembly of stacked cisternae after mitosis. Degron-tag rapid protein degradation, electron microscopy, immunofluorescence for tethering proteins The Journal of cell biology High 33301566
2025 A human loss-of-function variant in GORASP1 (c.1170_1171del; p.Asp390Glufs*18) causes complete absence of GRASP65 protein and results in a neurodevelopmental Golgipathy; patient cells and CRISPR-engineered RPE cells show hyposialylation (glycosylation defects) and mitotic delay (excess prometaphase/metaphase with polar chromosomes) without Golgi fragmentation. Patient variant identification, CRISPR/Cas9 recapitulation in RPE cells, glycosylation analysis (hyposialylation), cell cycle/mitosis analysis Life science alliance High 39933924
2026 Protein kinase D2 (PKD2) is an upstream regulator required for GRASP65 phosphorylation at S274 (human) and Golgi ribbon unlinking; PKD2 inhibition or depletion reduces GRASP65-S274 phosphorylation, decreases Golgi unlinking, and delays G2/M transition; PKD2-activating stimuli (phorbol esters, nocodazole) enhance GRASP65 phosphorylation in a PKD2-dependent manner. Phospho-specific antibody generation, PKD2 inhibitor treatment, siRNA depletion of PKD2, Golgi structure analysis, cell cycle assay Cells Medium 41892354

Source papers

Stage 0 corpus · 38 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
1997 GRASP65, a protein involved in the stacking of Golgi cisternae. Cell 364 9346242
2006 GM130 and GRASP65-dependent lateral cisternal fusion allows uniform Golgi-enzyme distribution. Nature cell biology 289 16489344
1998 Mapping the interaction between GRASP65 and GM130, components of a protein complex involved in the stacking of Golgi cisternae. The EMBO journal 210 9628863
2002 Caspase-mediated cleavage of the stacking protein GRASP65 is required for Golgi fragmentation during apoptosis. The Journal of cell biology 190 11815631
2003 A direct role for GRASP65 as a mitotically regulated Golgi stacking factor. The EMBO journal 167 12839990
2010 GRASP55 and GRASP65 play complementary and essential roles in Golgi cisternal stacking. The Journal of cell biology 164 20083603
2008 ERK regulates Golgi and centrosome orientation towards the leading edge through GRASP65. The Journal of cell biology 155 18762583
2005 Plk1 docking to GRASP65 phosphorylated by Cdk1 suggests a mechanism for Golgi checkpoint signalling. The EMBO journal 133 15678101
2004 Mapping the functional domains of the Golgi stacking factor GRASP65. The Journal of biological chemistry 127 15576368
2007 The yeast orthologue of GRASP65 forms a complex with a coiled-coil protein that contributes to ER to Golgi traffic. The Journal of cell biology 123 17261844
2005 The Golgi-associated protein GRASP65 regulates spindle dynamics and is essential for cell division. Molecular biology of the cell 121 15888544
2000 Peripheral Golgi protein GRASP65 is a target of mitotic polo-like kinase (Plk) and Cdc2. Proceedings of the National Academy of Sciences of the United States of America 112 11050165
2017 Knockout of the Golgi stacking proteins GRASP55 and GRASP65 impairs Golgi structure and function. Molecular biology of the cell 94 28814501
2010 The role of GRASP65 in Golgi cisternal stacking and cell cycle progression. Traffic (Copenhagen, Denmark) 82 20214750
2005 Convergence of cell cycle regulation and growth factor signals on GRASP65. The Journal of biological chemistry 79 15834132
2009 GRASP65 and GRASP55 sequentially promote the transport of C-terminal valine-bearing cargos to and through the Golgi complex. The Journal of biological chemistry 60 19840934
2020 Nonredundant Roles of GRASP55 and GRASP65 in the Golgi Apparatus and Beyond. Trends in biochemical sciences 58 32893104
2012 Sequential phosphorylation of GRASP65 during mitotic Golgi disassembly. Biology open 56 23259055
2015 JNK2 controls fragmentation of the Golgi complex and the G2/M transition through phosphorylation of GRASP65. Journal of cell science 55 25948586
2021 Rapid degradation of GRASP55 and GRASP65 reveals their immediate impact on the Golgi structure. The Journal of cell biology 47 33301566
2010 Mitotic inhibition of GRASP65 organelle tethering involves Polo-like kinase 1 (PLK1) phosphorylation proximate to an internal PDZ ligand. The Journal of biological chemistry 44 20937827
2014 GRASP65 controls the cis Golgi integrity in vivo. Biology open 43 24795147
2010 Caspase cleavage of the Golgi stacking factor GRASP65 is required for Fas/CD95-mediated apoptosis. Cell death & disease 43 21368855
2013 Structural insight into Golgi membrane stacking by GRASP65 and GRASP55 proteins. The Journal of biological chemistry 42 23940043
2015 Mena-GRASP65 interaction couples actin polymerization to Golgi ribbon linking. Molecular biology of the cell 40 26538023
2015 Structural basis for the interaction between the Golgi reassembly-stacking protein GRASP65 and the Golgi matrix protein GM130. The Journal of biological chemistry 34 26363069
2016 Phosphorylation of Golgi Peripheral Membrane Protein Grasp65 Is an Integral Step in the Formation of the Human Cytomegalovirus Cytoplasmic Assembly Compartment. mBio 31 27703074
2017 Shifted Golgi targeting of glycosyltransferases and α-mannosidase IA from giantin to GM130-GRASP65 results in formation of high mannose N-glycans in aggressive prostate cancer cells. Biochimica et biophysica acta. General subjects 20 28782625
2018 Inhibiting of GRASP65 Phosphorylation by DL-3-N-Butylphthalide Protects against Cerebral Ischemia-Reperfusion Injury via ERK Signaling. Behavioural neurology 18 30154935
2020 Markers of malignant prostate cancer cells: Golgi localization of α-mannosidase 1A at GM130-GRASP65 site and appearance of high mannose N-glycans on cell surface. Biochemical and biophysical research communications 17 32331836
2019 GRASP65 controls Golgi position and structure during G2/M transition by regulating the stability of microtubules. Traffic (Copenhagen, Denmark) 17 31336000
2016 Suppression of GRASP65 phosphorylation by tetrahydrocurcumin protects against cerebral ischemia/reperfusion injury via ERK signaling. Molecular medicine reports 17 27748926
2018 DjA1 maintains Golgi integrity via interaction with GRASP65. Molecular biology of the cell 13 30566031
2020 Biophysical characterization of intrinsically disordered human Golgi matrix protein GRASP65. International journal of biological macromolecules 8 32822731
2013 Crystallization and preliminary crystallographic studies of GRASP65 GRASP domain from Rattus norvegicus. Acta crystallographica. Section F, Structural biology and crystallization communications 3 23832210
2025 A biallelic variant in GORASP1 causes a novel Golgipathy with glycosylation and mitotic defects. Life science alliance 1 39933924
2026 Protein Kinase D2 Regulates GRASP65 Phosphorylation and Golgi Ribbon Unlinking During G2/M Transition. Cells 0 41892354
2025 Development and characterization of a membrane-permeant GRASP65-mimetic peptide that inhibits Golgi unlinking and cell cycle progression. Methods (San Diego, Calif.) 0 41338296

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