2qk2
From Proteopedia
Structural Basis of Microtubule Plus End Tracking by XMAP215, CLIP-170 and EB1
Structural highlights
FunctionMSPS_DROME Binds to the plus end of microtubules and regulates microtubule dynamics and microtubule organization. Promotes cytoplasmic microtubule nucleation and elongation. May act as a microtubule antipause factor that rapidly catalyzes the transition from pause to either growth or shrinkage. Involved in mitotic spindle elongation. Involved in the establishment of cell polarity and mitotic spindle orientation in neuroblasts. Required for maintaining the bipolarity of acentrosomal meiotic spindles; the function is dependent on tacc and involves ncd. Involved in oocyte microtubule cytoskeleton organization and bicoid mRNA localization. Seems to be involved in elongation of kinetochore-derived microtubule fibers.[1] [2] [3] [4] [5] [6] [7] [8] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedMicrotubule plus end binding proteins (+TIPs) localize to the dynamic plus ends of microtubules, where they stimulate microtubule growth and recruit signaling molecules. Three main +TIP classes have been identified (XMAP215, EB1, and CLIP-170), but whether they act upon microtubule plus ends through a similar mechanism has not been resolved. Here, we report crystal structures of the tubulin binding domains of XMAP215 (yeast Stu2p and Drosophila Msps), EB1 (yeast Bim1p and human EB1), and CLIP-170 (human), which reveal diverse tubulin binding interfaces. Functional studies, however, reveal a common property that native or artificial dimerization of tubulin binding domains (including chemically induced heterodimers of EB1 and CLIP-170) induces tubulin nucleation/assembly in vitro and, in most cases, plus end tracking in living cells. We propose that +TIPs, although diverse in structure, share a common property of multimerizing tubulin, thus acting as polymerization chaperones that aid in subunit addition to the microtubule plus end. Structural basis of microtubule plus end tracking by XMAP215, CLIP-170, and EB1.,Slep KC, Vale RD Mol Cell. 2007 Sep 21;27(6):976-91. PMID:17889670[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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