HUMAN RANBP3, A GROUP OF NUCLEAR RANGTP BINDING-PROTEINS

A group of novel human Ran-binding proteins, RanBP3, was identified us ing the yeast two-hybrid system via Ran-mediated interaction with the nucleotide exchange factor RCC1. Several open reading frames, represen ting putative alternatively spliced products, were established by cDNA cloning. Two of them, RanBP3-a and RanBP3-b, encode nuclear hydrophil ic proteins of 499 and 562 amino acid residues. The sequences contain FXFG motifs, characteristic of a subgroup of nucleoporins, and a C-ter minal domain showing similarity to the Ran-binding protein RanBP1, The se proteins are localized in the nucleus, preferentially bind RanGTP a nd may be nuclear effecters of the Ran pathway. (C) 1998 Federation of European Biochemical Societies.