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.
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.
Clifford
R
R
Department of Genetics, Washington University School of Medicine, Campus Box 8232, St Louis, MO 63110, USA.
Lee
M H
MH
Nayak
S
S
Ohmachi
M
M
Giorgini
F
F
Schedl
T
T
D020413:3' Untranslated Regions; D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D012734:Disorders of Sex Development / Q000235:genetics; D029721:Drosophila Proteins; D019143:Evolution, Molecular; D005260:Female; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D019849:Sex Determination Processes; D014157:Transcription Factors; D020798:Two-Hybrid System Techniques
D020413:3' Untranslated Regions; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C094448:GLD-1 protein, C elegans; D015801:Helminth Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D014157:Transcription Factors; C492171:fog-2 protein, C elegans; C066174:tra2 protein, Drosophila