PubMed Journals: J Biol Chem

  Source:		PMID: 11470801

    		J Biol Chem. 2001 Oct 5;276(40):37520-8.
     		Epub 2001 Jul 24.

			Identification of a novel kinesin-related
			protein, KRMP1, as a target for mitotic
			peptidyl-prolyl isomerase Pin1.

			Kamimoto T(1), Zama T, Aoki R, Muro Y, Hagiwara

			Author Information
			(1) Department of Functional Genomics, Medical
			Research Institute,
			Tokyo Medical and Dental University,
			1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510,

			Mitosis utilizes a number of kinesin-related
			proteins (KRPs). Here we report the identification
			of a novel KRP termed KRMP1, which has a
			deduced 1780-amino acid sequence composed
			of ternary domains. The amino-terminal head domain
			is most similar to the kinesin motor domain
			of the MKLP-1 subfamily and has an intrinsic
			ATPase activity that is diminished by substituting
			the consensus Lys-168 with Arg. The central
			stalk domain is predicted to form a long
			alpha-helical coiled-coil, and can interact
			with each other in vivo. An in vivo labeling
			experiment revealed that KRMP1 is phosphorylated,
			and we also found that the region within
			the tail domain containing Thr-1604 as the
			cdc2 kinase phosphorylation site differs
			from the bimC box conserved in the bimC
			subfamily of KRPs. Immunofluorescence analysis
			showed that endogenous KRMP1 was localized
			predominantly to the cytoplasm during interphase
			and dispersed throughout the cell during
			mitosis. Consistent with this finding, overexpressed
			KRMP1 was detected in a complicated nuclear
			or cytoplasmic pattern reflecting multiple
			nuclear localization/export signals. Furthermore,
			KRMP1 interacted with the mitotic peptidyl-prolyl
			isomerase Pin1 in vivo, and an in vitro
			interaction was detected between the tail
			domain of KRMP1 and the WW domain of Pin1.
			Overexpression of KRMP1 caused COS-7 cells
			to arrest at G(2)-M, and co-expression of
			Pin1 reversed this effect, indicating their
			physiological interaction. Together, our results
			suggest that KRMP1 is a mitotic target regulated
			by Pin1 and vice versa.

			DOI: 10.1074/jbc.M106207200 PMID: 11470801
			[Indexed for MEDLINE]

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