Function
DnaJ homolog subfamily A member 1 (DnaJA1) is a co-chaperone for HSPA8/Hsc70. DnaJA1 stimulates ATP synthesis and has a role in protein transport into mitochondria[1].
DnaJ homolog subfamily B member 1 (DnaJB1) interacts with HSP70. DnaJB1 stimulates ATP synthesis and the folding of unfolded proteins mediated by HSPA1A [2].
DnaJ homolog subfamily B member 6 (DnaJB6) acts as co-chaperone of HSP70. [3].
DnaJ homolog subfamily C member 2 (DnaJC2) acts as a chaperone for nascent polypeptide chains exiting the ribosome.
DnaJ homolog subfamily C member 3 (DnaJC3) acts as an inhibitor of the interferon-induced dsRNA-activated protein kinase.
DnaJ homolog subfamily C member 5 (DnaJC5) acts in membrane trafficking and protein folding.
DnaJ homolog subfamily C member 9 (DnaJC9) acts as co-chaperone of HSP70. [4].
DnaJ homolog subfamily C member 10 (DnaJC10) reduces incorrect disulfide bonds in misfolded glycoproteins.
Disease
DnaJA1 is down-regulated 5-fold in pancreatic cancer and is targeted as a biomarker for it.
Relevance
DnaA1 promotes apoptosis in response to cell stress mediated by exposure to UV[5].
Structural highlights
The interaction between DnaJB1 and the octapeptide C-terminal of Hsp70 includes various hydrogen bonds, salt bridges and hydrophobic interactions. The octapeptide assumes an extended conformation and forms an antiparallel β sheet with β2 domain I[6].
3D structures of DnaJ homolog
DnaJ homolog 3D structures
- ↑ Terada K, Mori M. Human DnaJ homologs dj2 and dj3, and bag-1 are positive cochaperones of hsc70. J Biol Chem. 2000 Aug 11;275(32):24728-34. PMID:10816573 doi:https://dx.doi.org/10.1074/jbc.M002021200
- ↑ Rauch JN, Gestwicki JE. Binding of human nucleotide exchange factors to heat shock protein 70 (Hsp70) generates functionally distinct complexes in vitro. J Biol Chem. 2014 Jan 17;289(3):1402-14. doi: 10.1074/jbc.M113.521997. Epub 2013 , Dec 5. PMID:24318877 doi:https://dx.doi.org/10.1074/jbc.M113.521997
- ↑ Izawa I, Nishizawa M, Ohtakara K, Ohtsuka K, Inada H, Inagaki M. Identification of Mrj, a DnaJ/Hsp40 family protein, as a keratin 8/18 filament regulatory protein. J Biol Chem. 2000 Nov 3;275(44):34521-7. PMID:10954706 doi:https://dx.doi.org/10.1074/jbc.M003492200
- ↑ Han C, Chen T, Li N, Yang M, Wan T, Cao X. HDJC9, a novel human type C DnaJ/HSP40 member interacts with and cochaperones HSP70 through the J domain. Biochem Biophys Res Commun. 2007 Feb 9;353(2):280-5. PMID:17182002 doi:10.1016/j.bbrc.2006.12.013
- ↑ Stark JL, Mehla K, Chaika N, Acton TB, Xiao R, Singh PK, Montelione GT, Powers R. Structure and function of human DnaJ homologue subfamily a member 1 (DNAJA1) and its relationship to pancreatic cancer. Biochemistry. 2014 Mar 4;53(8):1360-72. doi: 10.1021/bi401329a. Epub 2014 Feb 19. PMID:24512202 doi:https://dx.doi.org/10.1021/bi401329a
- ↑ Suzuki H, Noguchi S, Arakawa H, Tokida T, Hashimoto M, Satow Y. Peptide-binding sites as revealed by the crystal structures of the human Hsp40 Hdj1 C-terminal domain in complex with the octapeptide from human Hsp70. Biochemistry. 2010 Oct 5;49(39):8577-84. Epub 2010 Sep 9. PMID:20809635 doi:10.1021/bi100876n
