The RRE is a sequence of the HIV genome which is required for the export of the
unspliced mRNA from the nucleus to the cytoplasm. Previous studies show that RRE
on the HIV mRNA binds directly to Rev which then interacts with Ran and CRM 1 to
form an export complex. Our results indicate that Ran can interact with the RRE in
the absence of Rev and CRM 1 but in the presence of other factor(s) present in the nuclear extract. Ran-GEF or RCC 1 seems to be a potential mediating factor. Our
results suggest that Ran binds directly to RCC 1 and that the binding is disrupted by
addition of excess nucleotides and magnesimn. Our suggestion is that Ran and RCC 1
are members of an alternate export pathway present in the HIV. Our observation that the binding is nonspecific makes us speculate that this export pathway may be present
in other cell types as well.