Neuronal DnaJ proteins HSJ1a and HSJ1b: a role in linking the Hsp70 chaperone machine to the ubiquitin-proteasome system?
The heat-shock protein 70 chaperone machine is functionally connected to the ubiquitin-proteasome system by the co-chaperone CHIP. In this article, we discuss evidence that the neuronal DnaJ proteins HSJ1a and HSJ1b may represent a further link between the cellular protein folding and degradation machineries. We have demonstrated that HSJ1 proteins contain putative ubiquitin interaction motifs and can modulate the cellular processing of rhodopsin, a protein that is targeted for degradation by the proteasome when it is misfolded.
Division of Pathology, Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK. j.chapple@ucl.ac.uk
J P
JP
Chapple
J
J
van der Spuy
S
S
Poopalasundaram
M E
ME
Cheetham
D020816:Amino Acid Motifs; D050956:HSP40 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D012243:Rhodopsin / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism*
C121958:DNAJB2 protein, human; D050956:HSP40 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D025801:Ubiquitin; D012243:Rhodopsin; D046988:Proteasome Endopeptidase Complex