Peflin (PEF1)

PEF1 is a Ca(2+)-binding protein that belongs to the penta-EF hand (PEF) protein family. The deduced 284-amino acid protein has a calculated molecular mass of 30.3 kD. PEF1 contains an N-terminal hydrophobic domain, 5 C-terminal EF-hand motifs, and several potential phosphorylation sites. It shares about 30% amino acid identity with ALG2.

Peflin dissociated from ALG2 in the presence of Ca(2+), and the N-terminal hydrophobic domain of peflin was not essential for heterodimerization. Peflin and ALG2 colocalized in the cytoplasm, but ALG2 was also detected in nuclei, as revealed by immunofluorescence staining and subcellular fractionation. Peflin was recovered in the cytosolic fraction in the absence of Ca(2+) and in the membrane/cytoskeletal fraction in the presence of Ca(2+).