Characterization of RUSC1 and RUSC2 genes in silico.

We have previously cloned (or identified) and characterized novel genes encoding SH3 domain proteins, such as MAP3K10, FNBP1L, FNBP2, FCHSD1, FCHSD2, LASP2 and MPP7. During characterization of SH3 domain molecules, we found the existence of an N-terminally- truncated 433-aa RUSC1 protein (NP_055143.2). Here, we characterized RUSC1 and RUSC2 genes by using bioinformatics. IMAGE 5204626 (BC025680.1) and KIAA0375 (AB002373.2) were representative cDNAs derived from human RUSC1 and RUSC2 genes, respectively. 2210403N08 (AK039664.1) and MGC73483 (BC056360.1) cDNAs were derived from mouse Rusc1 gene, while Kiaa0375 (AK122263.1) cDNA was derived from mouse Rusc2 gene. RUSC1 gene, consisting of 11 exons, was mapped to human chromosome 1q22. RUSC2 gene, consisting of 12 exons was mapped to human chromosome 9p13. Human RUSC1 gene as well as mouse Rusc1 gene were found to encode two isoforms with or without 411-bp exon 3 due to alternative splicing of exon-skipping type. RUSC1 isoform 1 (1039 aa) and RUSC2 (1516 aa) showed 30.5% total amino-acid identity. Human RUSC1, RUSC2, mouse Rusc1 and Rusc2 proteins were found to share the common domain structure, consisting of RUN, Leucine zipper, and SH3 domains. RUSC1, RUSC2, RIPX, RUFY1, RUFY2, RUTBC1, RUTBC2, RUTBC3, RUB6IP1, and PLEKHM1 were RUN domain proteins within the human proteome. This is the first report on comprehensive characterization of RUSC1 and RUSC2 orthologs.