Characterization of the VHL tumor suppressor gene product: localization, complex formation, and the effect of natural inactivating mutations.
The human VHL tumor suppressor gene has been implicated in the inherited disorder von Hippel-Lindau disease and in sporadic renal carcinoma. The homologous rat gene encodes a 185-amino acid protein that is 88% sequence identical to the aligned 213-amino acid human VHL gene product. When expressed in COS-7 cells, both the human and the rat VHL proteins showed predominant nuclear, nuclear and cytosolic, or predominant cytosolic VHL staining by immunofluorescence. A complicated pattern of cellular proteins was seen that could be specifically coimmunoprecipitated with the introduced VHL protein. A complex containing VHL and proteins of apparent molecular masses 16 and 9 kDa was the most consistently observed. Certain naturally occurring VHL missense mutations demonstrated either complete or partial loss of the p16-p9 complex. Thus, the VHL tumor suppressor gene product is a nuclear protein, perhaps capable of specifically translocating between the nucleus and the cytosol. It is likely that VHL executes its functions via formation of specific multiprotein complexes. Identification of these VHL-associated proteins will likely clarify the physiology of this tumor suppressor gene.
Duan
D R
DR
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Humphrey
J S
JS
Chen
D Y
DY
Weng
Y
Y
Sukegawa
J
J
Lee
S
S
Gnarra
J R
JR
Linehan
W M
WM
Klausner
R D
RD
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002522:Chlorocebus aethiops; D018076:DNA, Complementary / Q000737:chemistry; D016147:Genes, Tumor Suppressor; D006367:HeLa Cells; D006801:Humans; D007668:Kidney; D008025:Ligases; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics* / Q000302:isolation & purification; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013347:Subcellular Fractions / Q000378:metabolism; D014162:Transfection; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D006623:von Hippel-Lindau Disease / Q000235:genetics*
D018076:DNA, Complementary; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D008025:Ligases; C497446:VHL protein, human