RUN And SH3 Domain Containing Protein 2 (RUSC2)

RUSC2 contains a RUN domain and an SH3 domain, as well as proline and glutamic acid-rich regions. The mouse homolog shares 84% similarity to human RUSC2. Northern blot analysis of human tissues detected ubiquitous expression of a 5.5-kb transcript, with highest levels in brain and testis. The RUN domain of RUSC2 mediated binding to Rab1. Western blot analysis detected a 220-kD protein mainly associated with membrane fractions. Immunofluorescence microscopy showed a cytosolic distribution with punctate perinuclear enrichment. RUSC2 interacted with the Rab1-binding protein GM130 (GOLGA2) on yeast 2-hybrid and in vitro binding assays.RT-PCR detected high expression in human kidney, ovary, and testis, followed by moderate expression in brain, placenta, lung, liver, and skeletal muscle, and low expression in prostate and small intestine.