OLIGOMERIZATION OF HIV-1 REV MUTANTS IN THE CYTOPLASM AND DURING NUCLEAR IMPORT

Oligomerization of Rev molecules has been shown to be required for Rev function. In addition to a Western blot assay monitoring dimer format ion, a new in vivo assay analyzing formation of Rev heteromers in the cytoplasm and during nuclear import is presented here. The oligomeriza tion assay is based upon the ability of Rev mutants with an intact nuc lear localization signal (NLS) to interact specifically with mutants w ith a defective NLS and translocate such mutants to the nuclear compar tments. Several of the mutants previously reported to be oligomerizati on defective were found to mediate nuclear and nucleolar localization of the NLS mutant. The Rev mutant previously named M4 was the only mut ant tested that did not translocate the mutant with a defective NLS to the nucleus. Furthermore, the predominantly cytoplasmic localization of the M4 mutant suggests that oligomerization is important for effect ive nuclear import of Rev. (C) 1997 Academic Press.