ISOLATION OF A MURINE CDNA CLONE ENCODING RAB19, A NOVEL TISSUE-SPECIFIC SMALL GTPASE

Using a rapid amplification of cDNA ends (RACE) cloning approach, we h ave isolated a cDNA clone encoding Rab19, a novel small GTPase of the Rab subfamily contained within partial sequences previously described [Chavrier et al., Gene 112 (1992) 261-264]. Northern blot analysis of the distribution of the rab19 mRNA in various adult mouse tissues and NIH 3T3 fibroblasts revealed that rab19 is expressed in a tissue-speci fic manner. The rab19 transcript was detected at high levels in intest ine, lung and spleen, and at a lower level in kidney. In contrast, liv er, brain, heart and NIH 3T3 fibroblasts contain only very little or n o detectable rnb19 mRNA. Therefore, Rab19 is likely to represent a nov el tissue- or cell type-specific small GTPase.