title: LAB-1 targets PP1 and restricts Aurora B kinase upon entrance into meiosis to promote sister chromatid cohesion.
abstract: Successful execution of the meiotic program depends on the timely establishment and removal of sister chromatid cohesion. LAB-1 has been proposed to act in the latter by preventing the premature removal of the meiosis-specific cohesin REC-8 at metaphase I in C. elegans, yet the mechanism and scope of LAB-1 function remained unknown. Here we identify an unexpected earlier role for LAB-1 in promoting the establishment of sister chromatid cohesion in prophase I. LAB-1 and REC-8 are both required for the chromosomal association of the cohesin complex subunit SMC-3. Depletion of lab-1 results in partial loss of sister chromatid cohesion in rec-8 and coh-4 coh-3 mutants and further enhanced chromatid dissociation in worms where all three kleisins are mutated. Moreover, lab-1 depletion results in increased Aurora B kinase (AIR-2) signals in early prophase I nuclei, coupled with a parallel decrease in signals for the PP1 homolog, GSP-2. Finally, LAB-1 directly interacts with GSP-1 and GSP-2. We propose that LAB-1 targets the PP1 homologs to the chromatin at the onset of meiosis I, thereby antagonizing AIR-2 and cooperating with the cohesin complex to promote sister chromatid association and normal progression of the meiotic program.
authors.affiliation: Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Yonatan B
authors.initials: YB
authors.lastname: Tzur
authors.forename: Carlos
authors.initials: C
authors.lastname: Egydio de Carvalho
authors.forename: Saravanapriah
authors.initials: S
authors.lastname: Nadarajan
authors.forename: Ivo
authors.initials: I
authors.lastname: Van Bostelen
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Gu
authors.forename: Diana S
authors.initials: DS
authors.lastname: Chu
authors.forename: Iain M
authors.initials: IM
authors.lastname: Cheeseman
authors.forename: Monica P
authors.initials: MP
authors.lastname: Colaiácovo
mesh_terms: D000818:Animals; D064107:Aurora Kinase B; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002842:Chromatids / Q000235:genetics / Q000378:metabolism*; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D042002:Chromatin Assembly and Disassembly; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D003434:Crossing Over, Genetic; D004260:DNA Repair; D049469:Meiotic Prophase I; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods; D054645:Protein Phosphatase 1 / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D013573:Synaptonemal Complex / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; C533197:LAB-1 protein, C elegans; D064107:Aurora Kinase B; D017346:Protein Serine-Threonine Kinases; C491506:air-2 protein, C elegans; D054645:Protein Phosphatase 1