Activator Of 90kDa Heat Shock Protein ATPase Homolog 1 (AHSA1)

The deduced 338-amino acid protein has a calculated molecular mass of 38.3 kD. Expression was below the level of detection in colon, thymus, spleen, small intestine, lung, and peripheral blood leukocytes. However, the authors identified AHSA1 sequences in colon, thymus, small intestine, lung, and blood EST databases, suggesting that AHSA1 expression is ubiquitous but variable. AHSA1 was primarily found in the cytosolic fraction of HeLa cell homogenates, with some in the microsomal membrane pellet. Immunofluorescence microscopy revealed strong cytosolic staining. When proteins were crosslinked prior to visualization, AHSA1 staining showed a more reticular pattern, suggesting that the crosslinker may have stabilized an association of AHSA1 with a tethering protein in the endoplasmic reticulum membrane.