Identification of a human HECT family protein with homology to the Drosophila tumor suppressor gene hyperplastic discs.
Use of the differential display technique to isolate progestin-regulated genes in T-47D human breast cancer cells led to identification of a novel gene, EDD. The cDNA sequence contains a 2799 amino acid open reading frame sharing 40% identity with the predicted 2894 amino acid product of the Drosophila melanogaster tumor suppressor gene hyperplastic discs, while the carboxy-terminal 889 amino acids show 96% identity to a rat 100 kDa HECT domain protein. EDD mRNA was progestin-induced in T-47D cells and was highly abundant in testes and expressed at moderately high levels in other tissues, suggesting a broad role for EDD. Anti-EDD antibodies immunoprecipitated an approximately 300 kDa protein from T-47D cell lysates. HECT family proteins function as E3 ubiquitin-protein ligases, targeting specific proteins for ubiquitin-mediated proteolysis. EDD is likely to function as an E3 as in vitro translated protein bound ubiquitin reversibly through a conserved HECT domain cysteine residue. EDD was localized by FISH to chromosome 8q22, a locus disrupted in a variety of cancers. Given the homology between EDD and the hyperplastic discs protein, which is required for control of imaginal disc growth in Drosophila, EDD potentially has a role in regulation of cell proliferation or differentiation.
Cancer Research Program, Garvan Institute of Medical Research, St Vincent's Hospital, Sydney, NSW, Australia.
M J
MJ
Callaghan
A J
AJ
Russell
E
E
Woollatt
G R
GR
Sutherland
R L
RL
Sutherland
C K
CK
Watts
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D002898:Chromosomes, Human, Pair 8; D003001:Cloning, Molecular; D004331:Drosophila melanogaster / Q000235:genetics*; D005821:Genetic Techniques; D015801:Helminth Proteins / Q000235:genetics; D006801:Humans; D008025:Ligases / Q000235:genetics / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D010453:Peptide Synthases; D011282:Pregnenediones / Q000494:pharmacology; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D051381:Rats; D017386:Sequence Homology, Amino Acid; D044767:Ubiquitin-Protein Ligases; D014452:Ubiquitins / Q000378:metabolism
D015801:Helminth Proteins; D011282:Pregnenediones; D011506:Proteins; D014452:Ubiquitins; C020175:16 alpha-ethyl-21-hydroxy-19-nor-4-pregnene-3,20-dione; C117617:UBR5 protein, human; D044767:Ubiquitin-Protein Ligases; D008025:Ligases; D010453:Peptide Synthases