title: Cep57, a multidomain protein with unique microtubule and centrosomal localization domains.
abstract: The present study demonstrates different functional domains of a recently described centrosomal protein, Cep57 (centrosomal protein 57). Endogenous Cep57 protein and ectopic expression of full-length protein or the N-terminal coiled-coil domain localize to the centrosome internal to gamma-tubulin, suggesting that it is either on both centrioles or on a centromatrix component. The N-terminus can also multimerize with the N-terminus of other Cep57 molecules. The C-terminus contains a second coiled-coil domain that directly binds to MTs (microtubules). This domain both nucleates and bundles MTs in vitro. This activity was also seen in vivo, as overexpression of full-length Cep57 or the C-terminus generates nocodazole-resistant MT cables in cells. Based on the present findings, we propose that Cep57 serves as a link with its N-terminus anchored to the centriole or centromatrix and its C-terminus to MTs.
authors.affiliation: Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.
authors.forename: Ko
authors.initials: K
authors.lastname: Momotani
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Khromov
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Miyake
authors.forename: P Todd
authors.initials: PT
authors.lastname: Stukenberg
authors.forename: Avril V
authors.initials: AV
authors.lastname: Somlyo
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins; D002460:Cell Line; D018385:Centrosome / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051379:Mice; D008870:Microtubules / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D011993:Recombinant Fusion Proteins; C482107:Tsp57 protein, mouse; D005982:Glutathione Transferase