GC-Rich Promoter Binding Protein 1 (GPBP1)

Bioinformatic analysis detected vasculin variants resulting from alternative splicing of exon 3. The variant containing a start codon in exon 3 encodes a deduced 473-amino acid protein with a calculated molecular mass of 53 kD. Screening of a multiple-tissue mRNA dot blot with an exon 3-specific probe showed expression only in vascular SMCs. A probe that recognized other variants detected expression in nearly all tissues examined.

Western blot analysis of atherosclerotic plaque lysates detected proteins with apparent molecular masses of 45 and 35 kD. The 45-kD protein was also detected in umbilical vein endothelial cells and plasma, and at lower levels in ovary and aorta. The 35-kD protein was detected in all tissues and cells examined.