6iwa

Crystal structure of Importin-alpha and phosphoserine GM130

spinqualitylabelsall models 6iwa, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6iwa is a 2 chain structure with sequence from Homo sapiens and Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.4Å Ligands: SEP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GOGA2_HUMAN Peripheral membrane component of the cis-Golgi stack that acts as a membrane skeleton that maintains the structure of the Golgi apparatus, and as a vesicle thether that facilitates vesicle fusion to the Golgi membrane. Together with p115/USO1 and STX5, involved in vesicle tethering and fusion at the cis-Golgi membrane to maintain the stacked and inter-connected structure of the Golgi apparatus. Plays a central role in mitotic Golgi disassembly: phosphorylation at Ser-37 by CDK1 at the onset of mitosis inhibits the interaction with p115/USO1, preventing tethering of COPI vesicles and thereby inhibiting transport through the Golgi apparatus during mitosis (By similarity). Also plays a key role in spindle pole assembly and centrosome organization (PubMed:26165940). Promotes the mitotic spindle pole assembly by activating the spindle assembly factor TPX2 to nucleate microtubules around the Golgi and capture them to couple mitotic membranes to the spindle: upon phosphorylation at the onset of mitosis, GOLGA2 interacts with importin-alpha via the nuclear localization signal region, leading to recruit importin-alpha to the Golgi membranes and liberate the spindle assembly factor TPX2 from importin-alpha. TPX2 then activates AURKA kinase and stimulates local microtubule nucleation. Upon filament assembly, nascent microtubules are further captured by GOLGA2, thus linking Golgi membranes to the spindle (PubMed:19242490, PubMed:26165940). Regulates the meiotic spindle pole assembly, probably via the same mechanism (By similarity). Also regulates the centrosome organization (PubMed:18045989, PubMed:19109421). Also required for the Golgi ribbon formation and glycosylation of membrane and secretory proteins (PubMed:16489344, PubMed:17314401).[UniProtKB:Q62839][UniProtKB:Q921M4] Publication Abstract from PubMed To facilitate proper mitotic cell partitioning, the Golgi disassembles by suppressing vesicle fusion. However, the underlying mechanism has not been characterized previously. Here, we report a Ran pathway-independent attenuation mechanism that allows Importin-alpha (a nuclear transport factor) to suppress the vesicle fusion mediated by p115 (a vesicular tethering factor) and is required for mitotic Golgi disassembly. We demonstrate that Importin-alpha directly competes with p115 for interaction with the Golgi protein GM130. This interaction, promoted by a phosphate moiety on GM130, is independent of Importin-beta and Ran. A GM130 K34A mutant, in which the Importin-alpha-GM130 interaction is specifically disrupted, exhibited abundant Golgi puncta during metaphase. Importantly, a mutant showing enhanced p115-GM130 interaction presented proliferative defects and G2/M arrest, demonstrating that Importin-alpha-GM130 binding modulates the Golgi disassembly that governs mitotic progression. Our findings illuminate that the Ran and kinase-phosphatase pathways regulate multiple aspects of mitosis coordinated by Importin-alpha (e.g. spindle assembly, Golgi disassembly). Ran pathway-independent regulation of mitotic Golgi disassembly by Importin-alpha.,Chang CC, Chen CJ, Grauffel C, Pien YC, Lim C, Tsai SY, Hsia KC Nat Commun. 2019 Sep 20;10(1):4307. doi: 10.1038/s41467-019-12207-4. PMID:31541088 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Importin 3D structures

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