Eic1 links Mis18 with the CCAN/Mis6/Ctf19 complex to promote CENP-A assembly.
CENP-A chromatin forms the foundation for kinetochore assembly. Replication-independent incorporation of CENP-A at centromeres depends on its chaperone HJURP(Scm3), and Mis18 in vertebrates and fission yeast. The recruitment of Mis18 and HJURP(Scm3) to centromeres is cell cycle regulated. Vertebrate Mis18 associates with Mis18BP1(KNL2), which is critical for the recruitment of Mis18 and HJURP(Scm3). We identify two novel fission yeast Mis18-interacting proteins (Eic1 and Eic2), components of the Mis18 complex. Eic1 is essential to maintain Cnp1(CENP-A) at centromeres and is crucial for kinetochore integrity; Eic2 is dispensable. Eic1 also associates with Fta7(CENP-Q/Okp1), Cnl2(Nkp2) and Mal2(CENP-O/Mcm21), components of the constitutive CCAN/Mis6/Ctf19 complex. No Mis18BP1(KNL2) orthologue has been identified in fission yeast, consequently it remains unknown how the key Cnp1(CENP-A) loading factor Mis18 is recruited. Our findings suggest that Eic1 serves a function analogous to that of Mis18BP1(KNL2), thus representing the functional counterpart of Mis18BP1(KNL2) in fission yeast that connects with a module within the CCAN/Mis6/Ctf19 complex to allow the temporally regulated recruitment of the Mis18/Scm3(HJURP) Cnp1(CENP-A) loading factors. The novel interactions identified between CENP-A loading factors and the CCAN/Mis6/Ctf19 complex are likely to also contribute to CENP-A maintenance in other organisms.
Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, UK.
Lakxmi
L
Subramanian
Nicholas R T
NR
Toda
Juri
J
Rappsilber
Robin C
RC
Allshire
D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism*; D002503:Centromere / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000378:metabolism*; D051548:Histone Acetyltransferases / Q000378:metabolism; D047468:Immunoprecipitation; D018386:Kinetochores / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
C477822:CTF19 protein, S cerevisiae; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; C410349:Cnp1 protein, S pombe; D003598:Cytoskeletal Proteins; C539322:Mis16 protein, S pombe; C539323:Mis18 protein, S pombe; C107314:Mis6 protein, S pombe; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D051548:Histone Acetyltransferases; C110880:histone acetyltransferase type B complex
CENP-A; Mis18; centromeres; epigenetics; fission yeast