HSP40, Hdj1 Antibody, Clone 3B9.E6

HSP40 proteins, also known as DnaJ homologs, form a large and diverse family of molecular co-chaperones defined by the presence of a conserved J-domain, typically located within the first 75 N-terminal amino acids. This domain is separated from the C-terminal region by a glycine/phenylalanine-rich linker and is critical for stimulating the ATPase activity of HSP70, thereby enhancing its ability to refold misfolded or aggregated proteins. Members of the HSP40 family, including the well-characterized Hdj1, are involved in a wide range of cellular processes such as protein folding, translocation, degradation, and the assembly of multi-protein complexes. In the nervous system, these functions are vital for maintaining proteostasis, especially under stress conditions that promote protein misfolding—a hallmark of neurodegenerative diseases like Alzheimer’s, Parkinson’s, and Huntington’s disease. HSP40-HSP70 complexes form the core of a larger chaperone network, interacting with co-factors such as Hip, Hop, HSP90, CHIP, and BAG-1 to direct client proteins toward refolding or degradation pathways. Differences among HSP40 subtypes, such as the presence of a zinc finger domain in HDJ2 and yeast Ydj1, further modulate their folding capabilities and functional specificity. Given their central role in regulating HSP70 activity and managing proteotoxic stress, HSP40 proteins are emerging as critical modulators of neuronal health and promising targets for therapeutic intervention in neurodegenerative disease research.

DNAJB1, HSP40, HSPF1, HDJ1, DNAJ1, DnaJ homolog subfamily B member 1, DnaJ protein homolog 1, Heat shock 40 kDa protein 1, Human DnaJ protein 1, hDj-1, heat shock protein 40

0.5 µg/ml of SMC-145 was sufficient for detection of HSP40 (HDJ1) in 15 µg of HeLa cell lysate by colorimetric immunoblot analysis using Goat anti-mouse IgG:HRP as the secondary antibody.

1. Cheetham M.E. and Caplan A.J. (1998) Cell Stress Chaperones 3: 28–36. 2. Fan C.Y., et al. (2003) Cell Stress Chaperones 8: 309–316. 3. Sohn S.Y., Kim S.B., Kim J., and Ahn B.Y. (2006) J Gen Virol. 87(7): 1883-91. 4. Liberek K. et al. (1991) Proc. Natl. Acad. Sci. USA 88: 2874–2878. 5. Cyr D.M., et al. (1992) J Biol Chem. 267: 20927–20931. 6. Höhfeld J., et al. (2001) EMBO Rep. 2: 885–890. 7. Terda K., et al. (1997) J Cell Biol. 139: 1089-1095. 8. Lu Z. and Cyr D.M. (1998) J Biol Chem. 273: 27824-27830.

1. Cheetham M.E. and Caplan A.J. (1998) Cell Stress Chaperones 3: 28–36. 2. Fan C.Y., et al. (2003) Cell Stress Chaperones 8: 309–316. 3. Sohn S.Y., Kim S.B., Kim J., and Ahn B.Y. (2006) J Gen Virol. 87 (7) : 1883-91. 4. Liberek K. et al. (1991) Proc. Natl. Acad. Sci. USA 88: 2874–2878. 5. Cyr D.M., et al. (1992) J Biol Chem. 267: 20927–20931. 6. Höhfeld J., et al. (2001) EMBO Rep. 2: 885–890. 7. Terda K., et al. (1997) J Cell Biol. 139: 1089-1095. 8. Lu Z. and Cyr D.M. (1998) J Biol Chem. 273: 27824-27830.