scholarly journals Heat Shock Protein 90 Ensures Efficient Mumps Virus Replication by Assisting with Viral Polymerase Complex Formation

2017 ◽  
Vol 91 (6) ◽  
Author(s):  
Hiroshi Katoh ◽  
Toru Kubota ◽  
Yuichiro Nakatsu ◽  
Maino Tahara ◽  
Minoru Kidokoro ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Measles Virus ◽  
Heat Shock Protein 90 ◽  
Mumps Virus ◽  
Viral Polymerase ◽  
Polymerase Complex ◽  
L Protein ◽  
Hsp90 Activity ◽  
The Stability

ABSTRACT Paramyxoviral RNAs are synthesized by a viral RNA-dependent RNA polymerase (RdRp) consisting of the large (L) protein and its cofactor phosphoprotein (P protein). The L protein is a multifunctional protein that catalyzes RNA synthesis, mRNA capping, and mRNA polyadenylation. Growing evidence shows that the stability of several paramyxovirus L proteins is regulated by heat shock protein 90 (Hsp90). In this study, we demonstrated that Hsp90 activity was important for mumps virus (MuV) replication. The Hsp90 activity was required for L-protein stability and activity because an Hsp90-specific inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), destabilized the MuV L protein and suppressed viral RNA synthesis. However, once the L protein formed a mature polymerase complex with the P protein, Hsp90 activity was no longer required for the stability and activity of the L protein. When the Hsp90 activity was inhibited, the MuV L protein was degraded through the CHIP (C terminus of Hsp70-interacting protein)-mediated proteasomal pathway. High concentrations of 17-AAG showed strong cytotoxicity to certain cell types, but combined use of an Hsp70 inhibitor, VER155008, potentiated degradation of the L protein, allowing a sufficient reduction of 17-AAG concentration to block MuV replication with minimum cytotoxicity. Regulation of the L protein by Hsp90 and Hsp70 chaperones was also demonstrated for another paramyxovirus, the measles virus. Collectively, our data show that the Hsp90/Hsp70 chaperone machinery assists in the maturation of the paramyxovirus L protein and thereby in the formation of a mature RdRp complex and efficient viral replication. IMPORTANCE Heat shock protein 90 (Hsp90) is nearly universally required for viral protein homeostasis. Here, we report that Hsp90 activity is required for efficient propagation of mumps virus (MuV). Hsp90 functions in the maintenance of the catalytic subunit of viral polymerase, the large (L) protein, prior to formation of a mature polymerase complex with the polymerase cofactor of L, phosphoprotein. Hsp70 collaborates with Hsp90 to regulate biogenesis of the MuV L protein. The functions of these chaperones on the viral polymerase may be common among paramyxoviruses because the L protein of measles virus is also similarly regulated. Our data provide important insights into the molecular mechanisms of paramyxovirus polymerase maturation as well as a basis for the development of novel antiviral drugs.

scholarly journals HSP90 Chaperoning in Addition to Phosphoprotein Required for Folding but Not for Supporting Enzymatic Activities of Measles and Nipah Virus L Polymerases

2016 ◽  
Vol 90 (15) ◽  
pp. 6642-6656 ◽  
Author(s):  
Louis-Marie Bloyet ◽  
Jérémy Welsch ◽  
François Enchery ◽  
Cyrille Mathieu ◽  
Sylvain de Breyne ◽  
...  
Keyword(s):  
Heat Shock ◽  
Measles Virus ◽  
Nipah Virus ◽  
Heat Shock Protein 90 ◽  
New Paradigm ◽  
Viral Polymerase ◽  
Content Type ◽  
N Terminus ◽  
Hsp90 Activity ◽  
Vesicular Stomatitis

ABSTRACTNonsegmented negative-stranded RNA viruses, or members of the orderMononegavirales, share a conserved gene order and the use of elaborate transcription and replication machinery made up of at least four molecular partners. These partners have coevolved with the acquisition of the permanent encapsidation of the entire genome by the nucleoprotein (N) and the use of this N-RNA complex as a template for the viral polymerase composed of the phosphoprotein (P) and the large enzymatic protein (L). Not only is P required for polymerase function, but it also stabilizes the L protein through an unknown underlying molecular mechanism. By using NVP-AUY922 and/or 17-dimethylaminoethylamino-17-demethoxygeldanamycin as specific inhibitors of cellular heat shock protein 90 (HSP90), we found that efficient chaperoning of L by HSP90 requires P in the measles, Nipah, and vesicular stomatitis viruses. While the production of P remains unchanged in the presence of HSP90 inhibitors, the production of soluble and functional L requires both P and HSP90 activity. Measles virus P can bind the N terminus of L in the absence of HSP90 activity. Both HSP90 and P are required for the folding of L, as evidenced by a luciferase reporter insert fused within measles virus L. HSP90 acts as a true chaperon; its activity is transient and dispensable for the activity of measles and Nipah virus polymerases of virion origin. That the cellular chaperoning of a viral polymerase into a soluble functional enzyme requires the assistance of another viral protein constitutes a new paradigm that seems to be conserved within theMononegaviralesorder.IMPORTANCEViruses are obligate intracellular parasites that require a cellular environment for their replication. Some viruses particularly depend on the cellular chaperoning apparatus. We report here that for measles virus, successful chaperoning of the viral L polymerase mediated by heat shock protein 90 (HSP90) requires the presence of the viral phosphoprotein (P). Indeed, while P protein binds to the N terminus of L independently of HSP90 activity, both HSP90 and P are required to produce stable, soluble, folded, and functional L proteins. Once formed, the mature P+L complex no longer requires HSP90 to exert its polymerase functions. Such a new paradigm for the maturation of a viral polymerase appears to be conserved in several members of theMononegaviralesorder, including the Nipah and vesicular stomatitis viruses.

scholarly journals Thermosensitization of tumor cells with inhibitors of chaperone activity and expression

2012 ◽  
Vol 58 (6) ◽  
pp. 662-672 ◽  
Author(s):  
V.A. Kudryavtsev ◽  
Y.M. Makarova ◽  
A.E. Kabakov
Keyword(s):  
Cell Death ◽  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Tumor Cells ◽  
De Novo ◽  
Heat Shock Protein 90 ◽  
Chaperone Activity ◽  
Hsp90 Activity ◽  
Hsp90 Chaperone

Effects of inhibitors of the heat shock protein 90 (HSP90) chaperone activity and inhibitors of the heat shock protein (HSP) expression on sensitivity of HeLa tumor cells to hyperthermia were studied. It was found that nanomolar concentrations of inhibitors of the HSP90 activity (17AAG or radicicol) slowed down chaperone-dependent reactivation of a thermo-labile reporter (luciferase) in heat-stressed HeLa cells and slightly enhanced their death following incubation for 60 min at 43°C. Herein, the inhibitors of HSP90 activity stimulated de novo induction of additional chaperones (HSP70 and HSP27) that significantly increased the intracellular HSP levels. If the cells were treated with 17AAG or radicicol along with an inhibitor of the HSP induction (e.g. quercetin or triptolid, or NZ28), this fully prevented the increase in intracellular chaperone levels resulting from the inhibition of HSP90 activity and subsequent heating. Importantly, in the case of conjunction of all the three treatments (an inhibitor of the HSP90 activity + an inhibitor of the HSP induction + 43°C for 60 min), the reporter reactivation was retarded yet stronger while the cell death was sharply (2-3-fold) enhanced. Such an enhancement of the cytotoxicity appears to occur owing to the "chaperone deficiency" when prior to heat stress both the functional activity of constitutive HSP90 and the expression of additional (inducible) chaperones are blocked in the cells.

scholarly journals Interaction of Heat Shock Protein 90 and the Co-chaperone Cpr6 with Ura2, a Bifunctional Enzyme Required for Pyrimidine Biosynthesis

2013 ◽  
Vol 288 (38) ◽  
pp. 27406-27414 ◽  
Author(s):  
Abbey D. Zuehlke ◽  
Nicholas Wren ◽  
Victoria Tenge ◽  
Jill L. Johnson
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Direct Interaction ◽  
Heat Shock Protein 90 ◽  
Pyrimidine Biosynthesis ◽  
Acceptor Site ◽  
Growth Defects ◽  
New Information ◽  
Hsp90 Activity ◽  
Dependent Growth

The molecular chaperone heat shock protein 90 (Hsp90) is an essential protein required for the activity and stability of multiple proteins termed clients. Hsp90 cooperates with a set of co-chaperone proteins that modulate Hsp90 activity and/or target clients to Hsp90 for folding. Many of the Hsp90 co-chaperones, including Cpr6 and Cpr7, contain tetratricopeptide repeat (TPR) domains that bind a common acceptor site at the carboxyl terminus of Hsp90. We found that Cpr6 and Hsp90 interacted with Ura2, a protein critical for pyrimidine biosynthesis. Mutation or inhibition of Hsp90 resulted in decreased accumulation of Ura2, indicating it is an Hsp90 client. Cpr6 interacted with Ura2 in the absence of stable Cpr6-Hsp90 interaction, suggesting a direct interaction. However, loss of Cpr6 did not alter the Ura2-Hsp90 interaction or Ura2 accumulation. The TPR domain of Cpr6 was required for Ura2 interaction, but other TPR containing co-chaperones, including Cpr7, failed to interact with Ura2 or rescue CPR6-dependent growth defects. Further analysis suggests that the carboxyl-terminal 100 amino acids of Cpr6 and Cpr7 are critical for specifying their unique functions, providing new information about this important class of Hsp90 co-chaperones.

Heat shock protein 90 regulates the stability of MEKK3 in HEK293 cells

2009 ◽  
Vol 259 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Shuping Fang ◽  
Jin Fu ◽  
Xia Yuan ◽  
Cui Han ◽  
Lijun Shi ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 90 ◽  
Hek293 Cells ◽  
The Stability

scholarly journals Heat Shock Protein 90 (Hsp90) Selectively Regulates the Stability of KDM4B/JMJD2B Histone Demethylase

2013 ◽  
Vol 288 (21) ◽  
pp. 14681-14687 ◽  
Author(s):  
Inbal Ipenberg ◽  
Noga Guttmann-Raviv ◽  
Hanan P. Khoury ◽  
Ilana Kupershmit ◽  
Nabieh Ayoub
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 90 ◽  
Histone Demethylase ◽  
The Stability
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