Multiple Rabaptin-5-like transcripts

Rabaptin-5 is an important component of intracellular vesicular transport machinery. In this report, we describe a novel Rabaptin-5gamma transcript which has a 120 nt deletion in coding region of Rabaptin-5 messenger RNA (mRNA). We also cloned the 5'part of Rabaptin-5delta transcript and showed that upstream previously described deletion, Rabaptin-5delta mRNA is identical to Rabaptin-5. Both deletions are in-frame and result in excision of 40 and 43 aa, respectively, from Rabaptin-5 polypeptide chain. We also detected Rabaptin-5delta and Rabaptin-5gamma transcripts in human. The results of Southern blot analysis and human genome sequence analysis strongly suggest that these transcripts along with Rabaptin-5 and Rabaptin-4 are encoded by a single gene, RAB5EP, and differ due to alternative pre-mRNA splicing. Although Rabaptin-5delta and Rabaptin-5gamma transcripts are low-abundant compared to Rabaptin-5 mRNA, their ubiquitous expression patterns might point on significant roles played by encoded by them proteins.