Germ cells carry out the reproductive function of the multicellular organisms, and normal germ cell development ensures survival of the species. Germ granules are conserved cytoplasmic organells of the germ cells, essential for the survival, differentiation, and function of these cells. Mutations in germ granule components or loss of their expression lead to infertility in model organisms and are associated with infertility in humans. By contrast, inappropriate expression of germ granule components in somatic cells is linked to carcinogenesis in humans. Many RNA-binding proteins and developmentally regulated mRNAs are found enriched in the germ granules, leading to a hypothesis that these organelles function in regulation of mRNA stability or translational activity;yet, the molecular function of these organelles is still undefined. The nematode C. elegans has been instrumental for understanding translational regulation of germline development. Our previous studies demonstrated specific contribution of C. elegans germ granules (P granules) to the regulation exerted by an RNA-binding regulatory protein FBF-2 in germline stem cells, yet much remains to be learned about the mechanistic basics of this contribution. Our experimental system is poised to address this question in molecular detail. Our studies will focus on FBF-2 as a paradigm of germ granule contribution to regulating the activity of RNA-binding proteins in germline. By integrating biochemical, molecular, genetic, and imaging-based approaches, we will: 1) Define the specific components of the FBF-2 regulatory complex;2) Identify the cofactors of FBF-2 that depend on P granule integrity for their assembly with FBF-2;3) Determine the sequences of FBF-2 mediating P granule recruitment and FBF-2-specific regulatory activity. These studies will reveal general mechanisms of germ granule-dependent regulation. Since the germ granules are conserved organelles and FBF-2 is a member of conserved PUF protein family, studies in this model system will provide critical insight into the causes of infertility in humans.

Public Health Relevance

Germ granules are conserved organelles essential for the development and function of the reproductive germ cells. Because of the significant conservation of germ cell regulatory machinery, studies of germ granule molecular function in C. elegans will illuminate the input of cytoplasmic organization of post-transcriptional regulators in human germ cells. This work is relevant to understanding potential underlying causes of human infertility or misregulation of germ-cell-specific regulatory pathways leading to carcinogenesis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
1R01GM109053-01
Application #
8613908
Study Section
Cellular, Molecular and Integrative Reproduction Study Section (CMIR)
Program Officer
Haynes, Susan R
Project Start
2014-03-01
Project End
2019-02-28
Budget Start
2014-03-01
Budget End
2015-02-28
Support Year
1
Fiscal Year
2014
Total Cost
$260,338
Indirect Cost
$70,338
Name
University of Montana
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
010379790
City
Missoula
State
MT
Country
United States
Zip Code
59812