ANALYSIS OF MEIOTIC CHROMOSOME SYNAPSIS IN YEAST
Principal Investigator: Nancy M Hollingsworth
Abstract: DESCRIPTION (provided by applicant): PROJECT SUMMARY Sexual reproduction requires the creation of haploid gametes from diploid cells. This two-fold reduction in chromosome number is carried out by a specialized, evolutionarily conserved, cell division called meiosis. In humans, failures in meiosis result in infertility and birth defects such as Trisomy 21 or Down Syndrome. Unique to meiosis is the first meiotic division, in which homologous pairs of sister chromatids segregate to opposite poles. To promote proper orientation at Metaphase I of meiosis, homologous chromosomes are physically connected by a combination of sister chromatid cohesion and reciprocal crossovers (COs). Meiotic recombination to generate COs is initiated by double strand breaks (DSBs). In mitotic cells, DSBs trigger the DNA damage checkpoint. In meiosis, programmed DSBs instead activate the meiosis-specific Mek1 kinase. Activated Mek1 then plays critical roles in promoting interhomolog (IH) recombination as well as arresting cells in meiotic prophase that fail to complete recombination. With a few exceptions, Mek1 substrates that regulate these processes are unknown. In budding yeast and mammals, there are two recombinases required for interhomolog (IH) recombination, the meiosis-specific Dmc1 protein and Rad51, which is also used in vegetative cells. Recent studies in budding yeast have shown that Dmc1 is responsible for repair of most meiotic DSBs with a bias towards IH recombination. The presence of the Rad51 protein, but not its strand exchange activity, is necessary to promote IH recombination, consistent with the down-regulation of Rad51 activity by Mek1. This grant tests the idea that Rad51 strand exchange activity instead mediates a temporally distinct round of intersister (IS) recombination triggered by, or coordinated with, resolution of Holliday junctions (HJs) to form COs. Cdc5 is a polo-like kinase in yeast whose activity is sufficient for HJ resolution. Development of a novel protocol has allowed the powerful proteomic approach of Stable Isotope Labeling by Amino acids in Cell culture or SILAC, to be applied to meiotic budding yeast cells for the first time. SILAC, combined with phospho-peptide purification and mass spectrometry (MS) will be used to identify Mek1 and Cdc5 substrates. Phenotypic analyses using a variety of approaches will then determine how phosphorylation of these substrates regulates key processes in meiosis such as IH bias, cohesion, synaptonemal complex formation and disassembly, the meiotic recombination checkpoint and HJ resolution. The knowledge gained from these studies is likely to be relevant to mammals, given the evolutionary conservation of meiosis between yeast and mammals.
Funding Period: 1995-01-01 - 2017-06-30
more information: NIH RePORT
- Deconstructing meiosis one kinase at a time: polo pushes past pachyteneNancy M Hollingsworth
Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794, USA
Genes Dev 22:2596-600. 2008..Determining the meiotic targets of Cdc5 therefore provides a new approach for identifying a eukaryotic Holliday resolvase...
- Regulation of meiotic recombination via Mek1-mediated Rad54 phosphorylationHengyao Niu
Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794 5215, USA
Mol Cell 36:393-404. 2009....
- Mek1 suppression of meiotic double-strand break repair is specific to sister chromatids, chromosome autonomous and independent of Rec8 cohesin complexesTracy L Callender
Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794 5215, USA
Genetics 185:771-82. 2010..The pattern of DSB repair in haploids containing Dmc1 and/or Rad51 indicates that Mek1 acts on Rad51-specific recombination processes...
- Using the semi-synthetic epitope system to identify direct substrates of the meiosis-specific budding yeast kinase, Mek1Hsiao Chi Lo
Department of Biochemistry and Cell Biology, Stony Brook University, New York, NY 11794 5215, USA
Methods Mol Biol 745:135-49. 2011..This method may be applicable to any kinase for which an analog-sensitive version is available. In addition, it provides a non-radioactive alternative for kinase assays with wild-type kinases...
- Cdc7-Dbf4 is a gene-specific regulator of meiotic transcription in yeastHsiao Chi Lo
Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, USA
Mol Cell Biol 32:541-57. 2012..Analysis of various phosphorylation site mutants suggests that Cdc7 functions with both Cdk1 and the meiosis-specific kinase Ime2 to control this critical transition point during meiosis...
- Down-regulation of Rad51 activity during meiosis in yeast prevents competition with Dmc1 for repair of double-strand breaksYan Liu
Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, United States of America
PLoS Genet 10:e1004005. 2014..These results support the idea that down-regulation of Rad51 activity is important during meiosis to prevent Rad51 from competing with Dmc1 for repair of meiotic DSBs. ..
- Characterization of a Meiotic Crossover Surveillance SystemJudith L Yanowitz; Fiscal Year: 2013..These complementary approaches will provide significant insights into a surveillance system that monitors crossover formation on each chromosome and allows for timely progression through meiosis. ..
- Synaptonemal complex assembly and function in meiosisMONICA P COLAIACOVO; Fiscal Year: 2013..The proposed research will investigate the molecular mechanisms promoting accurate meiotic chromosome segregation thereby laying the foundation for the development of effective preventive strategies. ..
- A PROGRAM OF RESEARCH IN POPULATION CYTOGENETICSTerry J Hassold; Fiscal Year: 2013..abstract_text> ..
- Genetic Recombination of c. ElegansAnne M Villeneuve; Fiscal Year: 2013....
- Establishment of sister chromatid cohesionDouglas E Koshland; Fiscal Year: 2013..Mutations in human genes encoding Smc proteins have been linked to cancer, birth defects and disorders. ..
- The Virtual Physiological Rat ProjectDaniel A Beard; Fiscal Year: 2013..This proposal targets the grand challenge of understanding complex multi-faceted disease phenotypes through experiments and simulations that capture the complex genotype-environment-phenotype relationship. ..
- Control of meiotic double strand break formationAndreas Hochwagen; Fiscal Year: 2013....
- The Synapsis Checkpoint in C. elegans MeiosisNeedhi Bhalla; Fiscal Year: 2013....
- Functional Analysis of the Dual Specificity Kinase NEK1 in Mammalian MeiosisJOANNA KIM HOLLOWAY; Fiscal Year: 2013..My progress in this direction will be assessed by regular meetings with my co-mentors, inter-departmental seminars on my research and, ultimately, by my publication record. ..
- Single Molecule Studies of Recombination and Chromosome Pairing in MeiosisRichard Fishel; Fiscal Year: 2013..Our unique single molecule approach should enhance the quantitative understanding of mechanical processes that lead to viable gamete formation as well as the fine line between dysfunctions that lead to infertility and genetic disease. ..
- Genomic Stability Functions of SMC Proteins in Germ CellsRaymond C Chan; Fiscal Year: 2013..The combination of these two approaches will provide an unbiased test for whether the loss of SMC-5/6 function contributes to aberrant genomic rearrangements. ..
- CELL CYCLE REGULATION DURING SPERMATOGENESISMary Ann Handel; Fiscal Year: 2013....
- Center for Neuroplasticity at the University of Puerto RicoSteven N Treistman; Fiscal Year: 2013..This UPR COBRE Center should define pathways and benchmarks for basic and translational research across the UPR system for the next decades. ..
- Meiotic Interactions of the RecA Homologue Dmc1Douglas K Bishop; Fiscal Year: 2013..Meiosis forms eggs and sperm. Understanding recombination may prevent birth defects caused by errors in meiosis. Recombination prevents cancer in humans, so this work may improve cancer prevention and treatment. ..
- The MRAD9 Radioresistance GeneHoward B Lieberman; Fiscal Year: 2013..abstract_text> ..
- The MLH1-MLH3 Heterodimer in Mammalian Meiotic Recombination and GameogenesisPAULA ELAINE COHEN; Fiscal Year: 2013..Together, these studies will contribute substantially to our knowledge of meiosis and, more specifically, to the important role of MLH1-MLH3 therein. ..
- Genetic Pathways Effecting Crossover Control and Meiotic Recombination in MammalsPAULA ELAINE COHEN; Fiscal Year: 2013....
- Chromosomal Control of Segregation of C. ElegansAbby F Dernburg; Fiscal Year: 2013..Through these approaches, we will learn how this molecular machine assembles from its component parts to govern the reassortment of genetic traits during sexual reproduction. ..
- Histone Chaperones and Acetyltransferases in Chromatin TransitionsJennifer K Nyborg; Fiscal Year: 2013..abstract_text> ..
- Role of Spo11 and recombination in mouse meiosisScott Keeney; Fiscal Year: 2013..In addition, a new method for genome-wide DSB mapping will be applied to Atm-/- spermatocytes to provide insight into the influence of ATM on the distribution of DSBs across the genome. ..
- Role of CDC14B in mouse oocyte maturationKAREN A SCHINDLER; Fiscal Year: 2013..Thus, the PI will be well-positioned to compete for additional funding and to have a successful independent research career. ..
- Regulation of meiotic recombination and chromosome segregation in mammalsKAREN MICHELE BERKOWITZ; Fiscal Year: 2013..Information gleaned from our studies will ultimately elucidate the molecular etiologies underlying chromosome mis- segregation and aneuploidy in humans. ..
- Recombination pathway and partner choice during C. elegans meiosisDIANA ELIZABETH LIBUDA; Fiscal Year: 2013..Overall, these studies will reveal how recombination pathway and partner preferences ensure that chromosomes form the connections necessary for chromosome segregation and repair DSBs for maintaining genomic integrity. ..
- Meiotic Centromere Behavior in YeastDean S Dawson; Fiscal Year: 2013....