Identification and characterization of a novel alternative splice variant of mouse GMx33α/GPP34

We have cloned and characterized a novel splice variant of mouse GMx33α/Golgi-associated protein of 34 kDa (GPP34), hereby designated GMx33αV/GPP34V. This splice variant skips the second and third exons, and the resulting frame shift generates a stop codon in the fourth exon. GMx33αV/GPP34V is comprised of 81 amino acid residues derived from the N-terminal end of the full length protein and corresponds to approximately one-third of the full length GMx33α/GPP34 sequence with a calculated molecular mass of 8900. In contrast to GMx33α/GPP34 mRNA which is expressed at similar levels in various tissues, GMx33αV/GPP34V mRNA was differentially expressed when examined by RT-PCR. Compared to other tissues, skeletal muscle showed relatively strong expression of GMx33αV/GPP34V mRNA. This splice variant cDNA was also detected in a human cell line.