Two novel human RAB genes with near identical sequence each map to a telomere-associated region: the subtelomeric region of 22q13.3 and the ancestral telomere band 2q13.

Two closely related genes have been identified at 2q13 and 22q13.3. These genes show similarity to members of the RAB family of small GTPases. RABL2A and RABL2B differ by three conservative amino acid changes over a total of 228 residues. Both are expressed in all tissues tested. Northern analysis showed that a 2.5-kb transcript is expressed in all tissues tested while a 1.4-kb transcript is specifically expressed only in muscle. The size difference between these two transcripts is the result of differential splicing of an intron within the 3' UTR. RABL2B is located within the subtelomeric region of 22q13.3. RABL2A maps to 2q13, the site of an ancestral telomere fusion event, suggesting that it also may be a subtelomeric gene.