The long-term objective of these studies is to determine how the expression of germ cell specific proteins is regulated post-transcriptionally during spermatogenesis. As a result of chromatin changes during spermiogenesis, post-transcriptional control plays an especially prominent role in regulating gene expression in the developing male gamete. Our past studies have identified a DNA/RNA-binding protein, Testis Brain RNA-binding protein (TB-RBP), that binds to conserved DNA sequences at chromosomal translocation breaks and to RNA sequences of mRNAs that are translationally regulated and transported.
In Specific Aim 1 we propose to determine how a TB-RBP interacting protein Trax modulates the nucleic acid binding activity of TB-RBP using transgenesis.
In Specific Aim 2, TB-RBP and mutated forms of TB-RBP will be over expressed to determine how a disruption in the ratio of TB-RBP and Trax affects spermatogenesis.
In Specific Aim 3, fertility and somatic cell function will be investigated using gene-targeted mice lacking TB-RBP.
In Specific Aim 4, the process whereby TB-RBP facilitates mRNA transport through intercellular bridges will be examined focusing on a kinesin and specific mRNAs encoded on sex chromosomes. These studies will provide important and novel data on critical mechanisms that regulate the expression of many testis-specific gene products essential for the production of functional spermatozoa. Moreover, our findings promise to extend far beyond spermatogenesis and have general applicability to translational regulation and mRNA transport in eukaryotic cells, since TB-RBP plays an important role in the transport and localization of a large number of mammalian brain mRNAs

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD028832-25
Application #
6874415
Study Section
Reproductive Biology Study Section (REB)
Program Officer
Taymans, Susan
Project Start
1980-09-01
Project End
2007-03-31
Budget Start
2005-04-01
Budget End
2006-03-31
Support Year
25
Fiscal Year
2005
Total Cost
$320,963
Indirect Cost
Name
University of Pennsylvania
Department
Obstetrics & Gynecology
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Xu, Mingang; McCarrey, John R; Hecht, Norman B (2008) A cytoplasmic variant of the KH-type splicing regulatory protein serves as a decay-promoting factor for phosphoglycerate kinase 2 mRNA in murine male germ cells. Nucleic Acids Res 36:7157-67
Yu, Zuoren; Hecht, Norman B (2008) The DNA/RNA-binding protein, translin, binds microRNA122a and increases its in vivo stability. J Androl 29:572-9
Xu, Mingang; Hecht, Norman B (2008) MSY2 and polypyrimidine tract binding protein 2 stabilize mRNAs in the mammalian testis. Int J Androl 31:457-61
Xu, Mingang; You, Yun; Hunsicker, Patricia et al. (2008) Mice deficient for a small cluster of Piwi-interacting RNAs implicate Piwi-interacting RNAs in transposon control. Biol Reprod 79:51-7
Iguchi, Naoko; Xu, Mingang; Hori, Tamaki et al. (2007) Noncoding RNAs of the mammalian testis: the meiotic transcripts Nct1 and Nct2 encode piRNAs. Ann N Y Acad Sci 1120:84-94
Xu, Mingang; Hecht, Norman B (2007) Polypyrimidine tract binding protein 2 stabilizes phosphoglycerate kinase 2 mRNA in murine male germ cells by binding to its 3'UTR. Biol Reprod 76:1025-33
Stein, Joel M; Bergman, Wayland; Fang, Yanshan et al. (2006) Behavioral and neurochemical alterations in mice lacking the RNA-binding protein translin. J Neurosci 26:2184-96
Iguchi, Naoko; Tobias, John W; Hecht, Norman B (2006) Expression profiling reveals meiotic male germ cell mRNAs that are translationally up- and down-regulated. Proc Natl Acad Sci U S A 103:7712-7
Yu, Zuoren; Raabe, Tobias; Hecht, Norman B (2005) MicroRNA Mirn122a reduces expression of the posttranscriptionally regulated germ cell transition protein 2 (Tnp2) messenger RNA (mRNA) by mRNA cleavage. Biol Reprod 73:427-33
Cho, Yoon Shin; Iguchi, Naoko; Yang, Juxiang et al. (2005) Meiotic messenger RNA and noncoding RNA targets of the RNA-binding protein Translin (TSN) in mouse testis. Biol Reprod 73:840-7

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