IDENTIFICATION OF A NOVEL RAN BINDING-PROTEIN-2 RELATED GENE (RANBP2L1) AND DETECTION OF A GENE-CLUSTER ON HUMAN-CHROMOSOME 2Q11-Q12

The giant 358-kDa protein Ran binding protein 2 (RanBP2/Nup358) is loc alized at the cytoplasmic side of the nuclear pore complex and likely constitutes the Ran-GTP binding site at the cytoplasmic face of the co mplex. RanBP2/Nup358 furthermore acts as a chaperone for red/green ops in molecules. Here, we report on the physical mapping of human RanBP2 between markers D2S340 and D2S1893. A duplication of the 5'-end sequen ce of RanBP2 occurs within 3 Mb distal to RanBP2. Detailed sequence an alysis resulted in primers specific for this distal duplication. Polym erase chain reaction-based screening of cDNA libraries indicates that this transcript, called RanBP2 alpha (HGMW-approved symbol RANBP2L1), is expressed in several tissues. Screening of a fetal brain cDNA libra ry yielded a 4057-bp partial cDNA clone for RanBP2 alpha. Its 5'-end i s almost identical to RanBP2, whereas its 3'-part is distinct from Ran BP2. Northern blot analysis using a probe of the 3'-untranslated seque nce of RanBP2 alpha detected in several tissues an 8-kb transcript rep resenting the full length of the transcript. In pancreas and placenta, an additional transcript of 14 kb was detected. PAC clones containing the bona fide RanBP2 sequences were localized to 2q11-q12 by FISH ana lysis, and a region of high similarity was detected on 2p11-p12. In su mmary, we have identified a RanBP2 gene cluster on 2q11-q12 together w ith a novel gene termed RanBP2 alpha, with high sequence similarity to RanBP2. (C) 1998 Academic Press.