An important von Hippel-Lindau tumor suppressor domain mediates Sp1-binding and self-association

VHL is the causative gene for both von Hippel-Lindau (VHL) disease and spor adic clear-cell renal cancer. We showed earlier that VHL downregulates vasc ular endo thelial growth factor transcription by directly binding and inhib iting the transcriptional activator Spl. We have now mapped the VHL Spl-bin ding domain to amino acids 96-122. The 96-122 domain is disproportionately affected by substitution mutations, which interfere with the VHL-Sp1 intera ction. Deletion of the 96-122 domain prevents VHL effects on Spl DNA bindin g and on VHL target gene expression, indicating the domain contributes impo rtantly to VHL tumor suppressor activity, Nevertheless, prevention of the V HL-Sp1 interaction only partially abrogates VHL's transcriptional repressor activity, supporting the existence of VHL transcriptional effecters in add ition to Spl. VHL also directly interacts with the Spl zinc fingers and sel f-associates via the 96-122 domain, which furthermore suggest the domain ma y bind other metalloproteins and contribute to VHL dominant-negative effect s. (C) 1999 Academic Press.