ATP Hydrolysis Is Required for the DnaJ-dependent Activation of DnaK Chaperone for Binding to Both Native and Denatured Protein Substrates

Wawrzynów, Alicja; Banecki, Bogdan; Wall, Daniel; Liberek, Krzysztof; Georgopoulos, Costa; Żylicz, Maciej

doi:10.1074/jbc.270.33.19307

Cited by 74 publications

(61 citation statements)

References 29 publications

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“…Because YDJ1 cannot substitute for auxilin, our results do not support a model where DnaJ homologs nonspecifically prime Hsc70 to bind substrates, particularly a model where the DnaJ homolog dissociates from Hsc70 before the substrate binds (31). Rather our results support a model where DnaJ homologs only present specific substrates to Hsc70; perhaps the substrates that bind to them.…”

Section: Resultscontrasting

confidence: 53%

Interaction of Auxilin with the Molecular Chaperone, Hsc70

Jiang

Greener

Barouch

et al. 1997

Journal of Biological Chemistry

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We have studied the direct interaction of the constitutive isoform of Hsp70 (Hsc70) with the DnaJ homolog, auxilin, a cofactor that binds to clathrin-coated vesicles and is required for their uncoating by Hsc70. Auxilin caused a 5-fold increase in Hsc70 ATPase activity and a corresponding increase in steady-state levels of bound ADP; the dissociation constant for this effect was 0.6 M. Auxilin also induced polymerization of Hsc70 and bound to the resulting polymer at a 1:1 molar ratio; here too the dissociation constant was 0.6 M. Both this binding and polymerization required ATP; the Hsc70 depolymerized with a 4-min half-life when ATP was completely hydrolyzed to ADP. Although auxilin induces polymerization stoichiometrically and other DnaJ homologs induce polymerization catalytically, these data show that auxilin is similar to other DnaJ homologs in its ability to activate the Hsc70 ATPase activity, to polymerize Hsc70, and in the nucleotide dependence of this polymerization. Furthermore, the 70-amino acid J-domain of auxilin polymerized Hsc70 with the same nucleotide dependence as intact auxilin. Therefore, although only auxilin and not other DnaJ homologs support uncoating, our data suggest that various DnaJ homologs share a common mechanism of interaction with Hsc70, perhaps because their J-domains interact similarly with Hsc70.

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Section: Resultscontrasting

confidence: 53%

Interaction of Auxilin with the Molecular Chaperone, Hsc70

Jiang

Greener

Barouch

et al. 1997

Journal of Biological Chemistry

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“…Refolding of denatured proteins required both domains of DnaJ: the J domain, which stimulates the ATPase activity of DnaK (17,22,23), and the binding substrate domain (23,24). Based on these observations, it was proposed that after the initial binding of the substrates to DnaJ, they were transferred to the peptide-binding site of DnaK (9 -11), which was also proposed to be activated by DnaJ for binding client proteins (22,25). More recently, a model has been put forward in which binding of DnaJ and ATP-DnaK to the same polypeptide chain leads to formation of ternary complexes.…”

mentioning

confidence: 99%

DnaJ Recruits DnaK to Protein Aggregates

Acebrón¹,

Fernández‐Sáiz²,

Taneva³

et al. 2008

Journal of Biological Chemistry

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Thermal stress might lead to protein aggregation in the cell. Reactivation of protein aggregates depends on Hsp100 and Hsp70 chaperones. We focus in this study on the ability of DnaK, the bacterial representative of the Hsp70 family, to interact with different aggregated model substrates. Our data indicate that DnaK binding to large protein aggregates is mediated by DnaJ, and therefore it depends on its affinity for the cochaperone. Mutations in the structural region of DnaK known as the "latch" decrease the affinity of the chaperone for DnaJ, resulting in a defective activity as protein aggregate-removing agent. As expected, the chaperone activity is recovered when DnaJ concentration is raised to overcome the lower affinity of the mutant for the cochaperone, suggesting that a minimum number of aggregate-bound DnaK molecules is necessary for its efficient reactivation. Our results provide the first experimental evidence of DnaJ-mediated recruiting of ATP-DnaK molecules to the aggregate surface.

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“…It has been shown that the simultaneous presence of DnaJ and ATP hydrolysis activates the DnaK protein for binding to different protein substrates (23). In the presence of substoichiometric concentrations of DnaJ and ATP, DnaK changes its own af nity to both denatured and native substrates (23,24).…”

Section: Hsp40 and Atp Hydrolysis Activates Hsp70 For Binding To Diffmentioning

confidence: 99%