HSP40 Antibody: APC

DnaJ/HSP40 proteins have been preserved throughout evolution and are important for protein translation, folding, unfolding, translocation, and degradation, primarily by stimulating the ATPase activity of chaperone proteins, HSP70s. Because the ATP hydrolysis is essential for the activity of HSP70s, DnaJ/HSP40 proteins actually determine the activity of HSP70s by stabilizing their interaction with substrate proteins. DnaJ/HSP40 proteins all contain the J domain through which they bind to HSP70s. HSP40, also known as HDJ1 (6), is a basic mammalian 40kDa heat shock protein which is not only homologous to the bacterial heat shock protein (DnaJ), but also yeast DnaJ-related proteins such as SCJ1, Sec63/Npl1, YDJ1 and SIS1 (2-5). HSP 40 is inducible by stress including heat after which is moves from the cytoplasm to the nucleus and nucleoli; an intracellular pattern similar to HSC70/HSP70, the mammalian homologues of the bacterial heat shock protein, DnaK (2).

1. Melville, M. W. et al. (1997) PNAS USA, 94: 97-102. 2. Hattori, H., Liu, Y-C., Tohnai, I., Ueda, M., Kaneda, T., Kobayashi, T., Tanabe, K., and Ohtsuka, K. (1992) Cell Structure and Function 17: 77-86. 3. Ohtsuka, K. Masuda, A., Nakai, A., and Nagata, K. (1990) Biochem. Biophys. Res. Commun. 166: 642-647. 4. Bardwell, J.C.A., Tilly, K., Craig, E., King, J., Zylicz, M. and Georgopoulos, C. (1986) J. Biol. Chem. 261: 1782-1785. 5. Ohku, M., Tamura, F., Nishimura, S., and Uchida, H. (1986) J. Biol. Chem. 261: 1778-1781. 6. Ohtsuka, K. (1993) Biochem. Biophys. Res. Commun. 197: 235-240.