The inner centromere protein (INCENP) has a modular organization, with domains required for chromosomal and cytoskeletal functions concentrated near the amino and carboxyl termini, respectively. In this study we have identified an autonomous centromere- and midbody-targeting module in the amino-terminal 68 amino acids of INCENP. Within this module, we have identified two evolutionarily conserved amino acid sequence motifs: a 13–amino acid motif that is required for targeting to centromeres and transfer to the spindle, and an 11–amino acid motif that is required for transfer to the spindle by molecules that have targeted previously to the centromere. To begin to understand the mechanisms of INCENP function in mitosis, we have performed a yeast two-hybrid screen for interacting proteins. These and subsequent in vitro binding experiments identify a physical interaction between INCENP and heterochromatin protein HP1Hsα. Surprisingly, this interaction does not appear to be involved in targeting INCENP to the centromeric heterochromatin, but may instead have a role in its transfer from the chromosomes to the anaphase spindle.
INCENP Centromere and Spindle Targeting: Identification of Essential Conserved Motifs and Involvement of Heterochromatin Protein HP1
Address correspondence to Dr. William Earnshaw, ICMB, University of Edinburgh, Michael Swann Building, Mayfield Road, Edinburgh Scotland, UK EH9 3JR. Tel.: (0131) 650-7101. Fax: (0131) 650-7100. E-mail: [email protected]
These experiments were supported by a grant from the Wellcome Trust, of which W.C. Earnshaw is a Principal Research Fellow.
Alexandra M. Ainsztein's present address is Laboratory of Molecular Embryology, NICHD, Building 18, Room 106, 18 Library Dr., MSC-5431, Bethesda, MD 20892-5431. Alastair M. Mackay's present address is Osiris Therapeutics, Inc., 2001 Aliceana St., Baltimore, MD 21231-2001.
Alexandra M. Ainsztein, Stefanie E. Kandels-Lewis, Alastair M. Mackay, William C. Earnshaw; INCENP Centromere and Spindle Targeting: Identification of Essential Conserved Motifs and Involvement of Heterochromatin Protein HP1 . J Cell Biol 28 December 1998; 143 (7): 1763–1774. doi: https://doi.org/10.1083/jcb.143.7.1763
Download citation file:
Sign in
Client Account
Sign in via your Institution
Sign in via your InstitutionSuggested Content
Email alerts
Advertisement
Advertisement