Asparaginase Like Protein 1 (ASRGL1)

The deduced 308-amino acid protein contains an O-glycosylation site, several putative phosphorylation sites, and a putative cleavage site for activation of the precursor protein into alpha and beta asparaginase subunits. The human and rat proteins share 77% identity. Northern blot analysis of rat tissues detected 2.5- and 1.4-kb transcripts.Highest expression was in testis, with lower expression in brain, liver, kidney, heart, and skeletal muscle, and no expression in spleen. Western blot analysis of human sperm extracts revealed 2 ALP peptides of 25 and 17 kD. Immunofluorescence visualization of fixed spermatozoa detected ALP expression at the midpiece, where it colocalized with a mitochondrial marker.