CRAHSP1 is a serine phosphoprotein initially identified as a physiological substrate for the Ca2+-calmodulin regulated protein phosphatase calcineurin (PP2B). CRAHSP1 interacts with the STYX/dead phosphate protein in developing spermatids and is a paralog of the brain-specific mRNA-binding protein PIPPIN. It is believed to have a common role in calcium-mediated signal transduction resulting from phosphorylation on serine residues Synonyms: Calcium-regulated heat stable protein 1, Calcium-regulated heat-stable protein of 24 kDa, CRHSP-24, CARHSP1, asCSDC1, MGC111446