Effect of heat shock on ribosome structure: appearance of a new ribosome-associated protein

1986 ◽  
Vol 6 (7) ◽  
pp. 2527-2535
Author(s):  
T W McMullin ◽  
R L Hallberg

After a nonlethal but heat shock protein-inducing hyperthermic treatment, ribosomes isolated from Tetrahymena thermophila contained an additional 22-kilodalton protein (p22). When maximally ribosome associated, this protein was found to be on the small subunit in a 1:1 stoichiometric ratio with other ribosomal proteins. Using an antiserum directed against the purified 22-kilodalton protein, we found that non-heat-shocked and heat-shocked cells contain identical amounts of this protein, the only difference being that in the stressed cells p22 is entirely ribosome bound, whereas in the unstressed cells p22 has little or no detectable ribosome association. Because the two-dimensional electrophoretic properties of p22 showed no alterations after heat shock, this change in state of ribosome-p22 interaction does not appear to be caused by a chemical modification of p22. When not strongly ribosome associated, p22 is not found free in the cytoplasm. During that time in heat shock when p22 is first becoming ribosome associated, it is found preferentially on polysomal ribosomes. Subsequently, all ribosomes, whether polysome bound or not, obtain a bound p22. The functional significance of this association is discussed.

1986 ◽  
Vol 6 (7) ◽  
pp. 2527-2535 ◽  
Author(s):  
T W McMullin ◽  
R L Hallberg

After a nonlethal but heat shock protein-inducing hyperthermic treatment, ribosomes isolated from Tetrahymena thermophila contained an additional 22-kilodalton protein (p22). When maximally ribosome associated, this protein was found to be on the small subunit in a 1:1 stoichiometric ratio with other ribosomal proteins. Using an antiserum directed against the purified 22-kilodalton protein, we found that non-heat-shocked and heat-shocked cells contain identical amounts of this protein, the only difference being that in the stressed cells p22 is entirely ribosome bound, whereas in the unstressed cells p22 has little or no detectable ribosome association. Because the two-dimensional electrophoretic properties of p22 showed no alterations after heat shock, this change in state of ribosome-p22 interaction does not appear to be caused by a chemical modification of p22. When not strongly ribosome associated, p22 is not found free in the cytoplasm. During that time in heat shock when p22 is first becoming ribosome associated, it is found preferentially on polysomal ribosomes. Subsequently, all ribosomes, whether polysome bound or not, obtain a bound p22. The functional significance of this association is discussed.


1993 ◽  
Vol 104 (3) ◽  
pp. 629-638 ◽  
Author(s):  
H. Hattori ◽  
T. Kaneda ◽  
B. Lokeshwar ◽  
A. Laszlo ◽  
K. Ohtsuka

We have previously reported that a novel 40 kDa protein is induced by heat shock and several environmental stresses in mammalian and avian cells and that the N-terminal amino acid sequence of this 40 kDa protein has homology with the bacterial DnaJ heat-shock protein. We have purified this protein (40 kDa heat-shock protein, hsp40) from HeLa cells by modified two-dimensional gel electrophoresis and generated a polyclonal antibody against hsp40. This antibody was highly specific for human hsp40 and cross-reacted weakly with rat and Chinese hamster hsp40. Indirect immunofluorescence revealed that the hsp40 in HeLa cells accumulates in the nucleus, especially in the nucleolus, during heat shock and returns to the cytoplasm during the recovery period. The kinetics of the accumulation in the nucleoli and subsequent return to the cytoplasm of hsp40 was similar to that of hsp70. In addition, hsp40 was co-localized with hsc70(p73) in heat-shocked HeLa cells as demonstrated by double immunofluorescence staining. These results suggest that hsp40 (a DnaJ homologue) and hsp70 (a DnaK homologue) may act in concert to repair (refold) denatured proteins and protein aggregates in the nuclei and nucleoli of heat-shocked HeLa cells.


1990 ◽  
Vol 10 (10) ◽  
pp. 5160-5165
Author(s):  
S Ahmad ◽  
R Ahuja ◽  
T J Venner ◽  
R S Gupta

A major cellular protein (P2; approximately 70 kilodaltons) which is altered in Chinese hamster ovary (CHO) cell mutants resistant to the microtubule inhibitors colchicine and podophyllotoxin has been shown to correspond to the constitutive form of the 70-kilodalton heat shock protein (hsc70). The inference that P2 and hsc70 are the same protein is based on the following observations: (i) migration of P2 in two-dimensional polyacrylamide gels in the same position as that reported for hsc70; (ii) cross-reactivity of a monoclonal antibody which reacts with both the constitutive and induced forms of hsp70 with the P2 spot from wild-type CHO cells and with both P2 and a mutant form of P2 in a CHO cell mutant; (iii) specific reactivity of a polyclonal antibody to P2 with both the constitutive and heat-induced forms of hsp70 in human cells; (iv) identical immunofluorescent staining of dot/patchlike structures with both P2 and hsp70 antibodies in human and CHO cells; and (v) a cDNA clone for hsc70 has been isolated and sequenced from wild-type CHO cells. The in vitro transcription and translation product of this cDNA has been shown to comigrate with the P2 protein spot in two-dimensional gels, indicating their identity. The fact that there is an alteration in hsc70 in mutants resistant to antimitotic drugs suggests a role for this protein in the in vivo assembly and function of microtubules.


2008 ◽  
Vol 127 ◽  
pp. S84
Author(s):  
Lotte Wieten ◽  
Ruurd van der Zee ◽  
Josee Wagenaar-Hilbers ◽  
Elles klein Koerkamp ◽  
Peter van Kooten ◽  
...  

1997 ◽  
Vol 18 (15) ◽  
pp. 2823-2831 ◽  
Author(s):  
Christian Scheler ◽  
Eva-Christina Müller ◽  
Joachim Stahl ◽  
Ursula Müller-Werdan ◽  
Johann Salnikow ◽  
...  

2019 ◽  
Author(s):  
Lei Wang ◽  
Yi Zhuo ◽  
Zhengwen He ◽  
Ying Xia ◽  
Ming Lu

AbstractObjectiveOur previous studies indicated that hyperthermia may play a role in differentiation of neural stem cells and that hypoxia inducible factor-1(HIF-1) was critical in this process. Heat shock protein 90 (Hsp90) is one of the most common heat-related proteins and involved in HIF-1 expression by regulating its activity and stabilization. Here, we hypothesized that HSP90 may be involved in regulation of hyperthermia-driven differentiation of neural stem cells(NSCs). We also investigated whether the HSP90 activity exert its regulatory action via HIF-1 pathway and the transcriptional level of the target genes of HIF-1.MethodThe cultured NSCs were divided into three groups: an hyperthermic treatment group(40NSC) which NSCs was induced under 40°C temperature; a control group(37NSC) which NSCs was induced under 37°C temperature; an hyperthermic treatment and HSP90-inhibited group(40NSC+GA) which NSCs was induced with 0.5μM HSP90 inhibitor Geldanamycin(GA) under 40°C temperature. We examined cells HSPa and HIF-1a expression during a time window of 5 days(12h, 1d, 3d, 5d) post-differentiation. The expression HSPα, HIF-1α, VEGF (vascular endothelial growth factor) and erythmpoietin(EPO) of during a time window was evaluated by RT-qPCR. The proportion of Tuj-1 positive differentiated cells were observed by flow cytometry.ResultHyperthermia promoted neuronal differentiation of NSC, and this effect could be blocked by HSP90 inhibitor GA. We observed the up-regulation of HSP90 during hyperthermia treatment, and that the protein levels of HIF-1α changed depending of the GA treatment. GA could not inhibited HSP90α expression but suppressed HSP activity and decreased the expression HIF-1α protein. Inhibition of HIF-1α expression by GA could consequently affect expression of its targeted genes such as VEGF and EPO.ConclusionHyperthermia promote differentiation of NSCs into neurons. HSP90 involved in the regulation of hyperthermia-driven differentiation of NSC, and the mechanism is related to HIF-1α and its downstream gene activation.


1986 ◽  
Vol 6 (6) ◽  
pp. 2267-2270
Author(s):  
R L Hallberg

For Tetrahymena thermophila cells to survive at 43 degrees C, a normally lethal temperature, they require a pretreatment which either elicits the synthesis of heat shock proteins or one which brings about a change in the translational machinery of the cell such that is is not inactivated when transferred to 43 degrees C. In this report I present evidence showing that the latter modification can occur in the complete absence of protein synthesis, indicating that heat shock protein production is not required for the induced thermostabilization of the translational machinery.


Sign in / Sign up

Export Citation Format

Share Document