Target recognition of RNA-binding protein GLD-1

摘要

Germline and early development of various organisms is highly dependent on the temporal and spatial control of maternal gene products. In Caenorhabditis elegans, one of the major regulators of maternal mRNA expression in the germline is an RNA-binding protein, GLD-1 (GermLine Development defective). This maxi-KH motif containing RNA-binding protein has various functions mainly during female germ cell development, suggesting that it likely controls the expression of a selective group of maternal mRNAs. In order to gain insight into how GLD-1 specifically recognizes these mRNA targets, Dr Jung Doh and colleagues identified 38 biochemically proven GLD-1 binding regions from multiple mRNA targets that are among over 100 putative targets co-immu-noprecipitated with GLD-1. Computational analyses revealed three over-represented and phylogenetically conserved sequence motifs. The authors found that two of the motifs, one of which is novel, are important for GLD-1 binding in four GLD-1 mRNAs. Furthermore, they demonstrated the ability of secondary structure to obscure a GLD-1 binding motif and that the functionality of a GLD-1 binding motif is dependent on the surrounding sequences. Taken together, the study data suggest that some mRNAs recruit GLD-1 by a distinct mechanism, which involves more than one sequence motif that needs to be embedded in the correct context and structural environment.