Nematode CDC-37 and DNJ-13 form complexes and can interact with HSP-90

Nematode CDC-37 and DNJ-13 form complexes and can interact with HSP-90

Blog Article

Abstract The molecular chaperones Hsc70 and Hsp90 are required for proteostasis control and specific folding of client proteins in eukaryotic and prokaryotic organisms.Especially in eukaryotes these ATP-driven molecular chaperones are interacting with cofactors that specify the client spectrum and coordinate the ATPase cycles.Here we find that a Hsc70-cofactor of the Hsp40 boxes family from nematodes, DNJ-13, directly interacts with the kinase-specific Hsp90-cofactor CDC-37.The interaction is specific for DNJ-13, while DNJ-12 another DnaJ-like protein of C.elegans, does not bind to CDC-37 in a similar manner.

Analytical ultracentrifugation is employed to show that one CDC-37 molecule binds to a dimeric DNJ-13 protein with low micromolar affinity.We perform cross-linking studies with mass spectrometry to identify the interaction site and obtain specific cross-links connecting the N-terminal J-domain of DNJ-13 with the N-terminal domain of CDC-37.Further AUC experiments reveal that both, the N-terminal part of CDC-37 and Drone the C-terminal domain of CDC-37, are required for efficient interaction.Furthermore, the presence of DNJ-13 strengthens the complex formation between CDC-37 and HSP-90 and modulates the nucleotide-dependent effects.These findings on the interaction between Hsp40 proteins and Hsp90-cofactors provide evidence for a more intricate interaction between the two chaperone systems during client processing.