Girdin (GRDN)

The deduced 1,870-amino acid protein has a calculated molecular mass of 220 kD. Girdin contains 135 continuous heptad repeats typical of alpha-helical coiled-coil proteins. Northern blot analysis detected variable expression of a 9.5-kb transcript in all tissues examined. Western blot analysis of human brain and testis lysates detected girdin at an apparent molecular mass of 250 kD. Endogenous monkey girdin formed oligomers in COS-7 cells, and mutation analysis indicated that its N-terminal domains facilitated oligomerization.GIV also has several putative peroxisomal targeting signals within the coiled-coil domain and an ATP/GTP-binding site within the C-terminal domain. Western blot analysis detected GIV at an apparent molecular mass of 200 kD in several rat tissues and in all cell lines examined, including human cell lines.