Akay, Alper et al. (2011) International Worm Meeting "RNA-binding Protein GLD-1 Genetically Interacts with Multiple miRNA Pathways in C. elegans."

Gartner, Anton, Akay, Alper, Hutvagner, Gyorgy, Lehrbach, Nicolas, Miska, Eric, Craig, Ashley

[International Worm Meeting, 2011]

GLD-1 is a member of a highly conserved RNA-binding protein family, characterised by the KH domain. In C. elegans GLD-1 functions throughout the germ-line in developmental processes such as mitosis/meiosis transition and spermatogenesis/oogenesis decisions, through translational regulation of various targets. In addition, GLD-1 has a key role in DNA damage-induced germ-line apoptosis through control of cep-1/p53 mRNA levels. In order to study GLD-1 target specificity and the molecular mechanisms that control GLD-1 function, we performed two genetic screens using the temperature sensitive hypomorphic gld-1(op236) allele. In our enhancer screen we found that RNAi-mediated knock-down of nhl-2 and vig-1 specifically caused sterility in gld-1(op236) worms, at the permissive temperature. As both vig-1 and nhl-2 have been shown to interact with the miRNA-induced silencing complex (miRISC) and are required for miRNA function, our results indicated a possible genetic interaction between gld-1 and miRNA-mediated translational regulation. We indeed find that vig-1 and nhl-2 mutants have embryonic lethality and sterility in the gld-1(op236) mutant background. Furthermore, gld-1(op236) enhances the phenotypes associated with the loss of let-7 and mir-35 family miRNAs. In weak let-7(mg279) mutant worms gld-1(op236) enhances the phenotypes associated with larval to adult transition, suggesting a role for gld-1 in the heterochronic pathway. In mir-35 family mutants gld-1(op236) enhances the embryonic and larval lethality. Taken together, our data supports the hypothesis of a genetic interaction between GLD-1 and several miRNA pathways. In further support of our hypothesis, we identified ALG-1, CGH-1 and PAB-1 as direct interactors of GLD-1. We are currently investigating the roles of the direct interactors identified, in GLD-1 mediated translational regulation and the possibility of common targets between GLD-1 and miRNAs.

Akay, Alper et al. (2010) C. elegans: Development and Gene Expression, EMBL, Heidelberg, Germany "Novel Genetic Interactors of the C. elegans RNA-binding Protein GLD-1"

Bajan, Sarah, Rutkowski, Rachael, Akay, Alper, Gartner, Anton, Hutvagner, Gyorgy, Craig, Ashley

[C. elegans: Development and Gene Expression, EMBL, Heidelberg, Germany, 2010]

GLD-1 is a member of a highly conserved RNA-binding protein family, characterised by the KH domain. In C. elegans, GLD-1 functions throughout the germ-line in developmental processes such as mitosis/meiosis transition and spermatogenesis/oogenesis decisions, through translational regulation of various targets. In addition, GLD-1 has a key role in DNA damage-induced germ-line apoptosis through control of cep-1/p53 mRNA levels. In order to study GLD-1 target specificity and the molecular mechanisms that control GLD-1 function, we performed two genetic screens using the temperature sensitive gld-1(op236) allele. In our enhancer screen we found that RNAi-mediated knock-down of nhl-2 and vig-1 sp ecifically caused sterility in gld-1(op236) worms, at the permissive temperature. As both vig-1 and nhl-2 have been shown to interact with the miRNA-induced silencing complex (miRISC) and are required for miRNA function, our results indicate a possible genetic interaction between gld-1 and miRNA-mediated translational regulation. In fact, gld-1(op236) enhances several phenotypes of the weak let-7(mg279) allele. We are currently investigating possible genetic interactions between GLD-1 and miRNA pathway genes, as well as direct interactions with individual miRNAs. We are also applying biochemical methods to identify proteins which directly interact with GLD-1. Results from both genetic and biochemical experiments will help us to better understand the role of GLD-1 in translational regulation.