Authors: Clifford R; Lee MH; Nayak S; Ohmachi M; Giorgini F; Schedl T
Abstract: Male sex determination in the Caenorhabditis elegans hermaphrodite germline requires translational repression of tra-2 mRNA by the GLD-1 RNA binding protein. We cloned fog-2 by finding that its gene product physically interacts with GLD-1, forming a FOG-2/GLD-1/tra-2 3'untranslated region ternary complex. FOG-2 has an N-terminal F-box and a novel C-terminal domain called FTH. Canonical F-box proteins act as bridging components of the SCF ubiquitin ligase complex; the N-terminal F-box binds a Skp1 homolog, recruiting ubiquination machinery, while a C-terminal protein-protein interaction domain binds a specific substrate for degradation. However, since both fog-2 and gld-1 are necessary for spermatogenesis, FOG-2 cannot target GLD-1 for ubiquitin-mediated degradation. We propose that FOG-2 also acts as a bridge, bringing GLD-1 bound to tra-2 mRNA into a multiprotein translational repression complex, thus representing a novel function for an F-box protein. fog-2 is a member of a large, apparently rapidly evolving, C. elegans gene family that has expanded, in part, by local duplications; fog-2 related genes have not been found outside nematodes. fog-2 may have arisen during evolution of self-fertile hermaphroditism from an ancestral female/male species.
Keywords: 3' Untranslated Regions; Alleles; Amino Acid Sequence; Animals; *Caenorhabditis elegans Proteins; DNA-Binding Proteins/genetics/*physiology; Disorders of Sex Development/genetics; *Drosophila Proteins; Evolution, Molecular; Female; Genes, Helminth; Helminth Proteins/*metabolism; Male; Molecular Sequence Data; Multigene Family; Protein Biosynthesis; RNA, Messenger/genetics; RNA-Binding Proteins/*metabolism; Ribonucleoproteins/genetics; Sequence Homology, Amino Acid; *Sex Determination Processes; *Transcription Factors; Two-Hybrid System Techniques|
Journal: Development (Cambridge, England) Volume: 127 Issue: 24 Pages: 5265-76 Date: Nov. 15, 2000 PMID: 11076749 |
Clifford R, Lee MH, Nayak S, Ohmachi M, Giorgini F, Schedl T (2000) FOG-2, a novel F-box containing protein, associates with the GLD-1 RNA binding protein and directs male sex determination in the C. elegans hermaphrodite germline. Development (Cambridge, England) 127: 5265-76.
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