Detection and characterization of mRNA and proteins encoded by human rab2 low molecular weight GTP-binding protein gene.

Three RNA species of 3.5, 2.4 and 1.4 kb were detected in all human hematopoietic, fibroblastic and tumor cell lines examined, as the mRNA of human rab2 gene presumably involved in intracellular transport. The mRNA differed in the length of the 3'-non-translated regions due to termination and/or processing at the alternative polyadenylation sites. The 1.4-kb rab2 RNA was predominant in Molt-4 and U-937 of mononuclear cell origin, while the 2.4-kb RNA was dominant in the other cells examined. The degradation of all rab2 RNA was similar and as slow as beta-actin RNA. The rab2 proteins were ubiquitously detected in the human cells as two phosphorylated peptides of major pp24rab2 and minor pp25rab2. pp25rab2 was slightly more phosphorylated than pp24rab2. Both rab2 proteins were abundantly detected in neural PC12 and NB3 cells, and mostly pp24rab2 was produced in the other human and rodent cells.