The response of the centrosome to heat shock and related stresses in a Drosophila cell line

1990 ◽  
Vol 96 (3) ◽  
pp. 403-412
Author(s):  
A. Debec ◽  
A.M. Courgeon ◽  
M. Maingourd ◽  
C. Maisonhaute
Keyword(s):  
Heat Shock ◽  
Microtubule Assembly ◽  
Close Link ◽  
Drosophila Cell ◽  
Shock Response ◽  
Kinetics Of ◽  
Drosophila Cell Line ◽  
Good Agreement ◽  
Cell Division Control

The centrosome of Drosophila melanogaster cells cultured in vitro has been followed by immunofluorescence techniques with the Bx63 antibody of Frasch and Saumweber. After a heat shock, the centrosome labelling becomes very small and finally disappears after 30 min. Other heat-shock protein (hsp) inducers such as ethanol, arsenite and ecdysterone lead to the same disappearance. Moreover, the functional ability of centrosomes to nucleate microtubule assembly is inhibited by these treatments, particularly by heat shock, ethanol and ecdysterone. Two other hsp inducers, cadmium chloride and hydrogen peroxide, do not affect the centrosome seriously. With the exception of cadmium, the rapidity and the intensity of hsp induction are in good agreement with the kinetics of alteration of the organelle. We propose that a close link exists between the heat-shock response and the centrosome and that the physiological induction of hsps could be reinterpreted in terms of cell division control.

p38β-regulated induction of the heat shock response by carbon monoxide releasing molecule CORM-2 mediates cytoprotection in lung cells in vitro

2011 ◽  
Vol 670 (1) ◽  
pp. 58-66 ◽  
Author(s):  
Nils Schallner ◽  
Sven Schwemmers ◽  
Christian I. Schwer ◽  
Christian Froehlich ◽  
Patrick Stoll ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Lung Cells ◽  
Shock Response

scholarly journals Serine Protease HtrA1 Associates with Microtubules and Inhibits Cell Migration

2009 ◽  
Vol 29 (15) ◽  
pp. 4177-4187 ◽  
Author(s):  
Jeremy Chien ◽  
Takayo Ota ◽  
Giovanni Aletti ◽  
Ravi Shridhar ◽  
Mariarosaria Boccellino ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Shock ◽  
Cell Motility ◽  
Serine Proteases ◽  
Microtubule Assembly ◽  
Unfolded Proteins ◽  
Microtubule Stability ◽  
Enhanced Expression

ABSTRACT HtrA1 belongs to a family of serine proteases found in organisms ranging from bacteria to humans. Bacterial HtrA1 (DegP) is a heat shock-induced protein that behaves as a chaperone at low temperature and as a protease at high temperature to help remove unfolded proteins during heat shock. In contrast to bacterial HtrA1, little is known about the function of human HtrA1. Here, we report the first evidence that human HtrA1 is a microtubule-associated protein and modulates microtubule stability and cell motility. Intracellular HtrA1 is localized to microtubules in a PDZ (PSD95, Dlg, ZO1) domain-dependent, nocodazole-sensitive manner. During microtubule assembly, intracellular HtrA associates with centrosomes and newly polymerized microtubules. In vitro, purified HtrA1 promotes microtubule assembly. Moreover, HtrA1 cosediments and copurifies with microtubules. Purified HtrA1 associates with purified α- and β-tubulins, and immunoprecipitation of endogenous HtrA1 results in coprecipitation of α-, β-, and γ-tubulins. Finally, downregulation of HtrA1 promotes cell motility, whereas enhanced expression of HtrA1 attenuates cell motility. These results offer an original identification of HtrA1 as a microtubule-associated protein and provide initial mechanistic insights into the role of HtrA1 in theregulation of cell motility by modulating microtubule stability.

scholarly journals A simplified mathematical model of directional DNA site-specific recombination by serine integrases

2017 ◽  
Vol 14 (126) ◽  
pp. 20160618 ◽  
Author(s):  
Alexandra Pokhilko ◽  
Jia Zhao ◽  
W. Marshall Stark ◽  
Sean D. Colloms ◽  
Oliver Ebenhöh
Keyword(s):  
Mathematical Model ◽  
Site Specific ◽  
Site Specific Recombination ◽  
Thermodynamic Driving Force ◽  
Necessary And Sufficient ◽  
Kinetics Of ◽  
Inactive Protein ◽  
Core Features ◽  
Good Agreement

Serine integrases catalyse site-specific recombination to integrate and excise bacteriophage genomes into and out of their host's genome. These enzymes exhibit remarkable directionality; in the presence of the integrase alone, recombination between attP and attB DNA sites is efficient and irreversible, giving attL and attR products which do not recombine further. However, in the presence of the bacteriophage-encoded recombination directionality factor (RDF), integrase efficiently promotes recombination between attL and attR to re-form attP and attB . The DNA substrates and products of both reactions are approximately isoenergetic, and no cofactors (such as adenosine triphosphate) are required for recombination. The thermodynamic driving force for directionality of these reactions is thus enigmatic. Here, we present a minimal mathematical model which can explain the directionality and regulation of both ‘forward’ and ‘reverse’ reactions. In this model, the substrates of the ‘forbidden’ reactions (between attL and attR in the absence of RDF, attP and attB in the presence of RDF) are trapped as inactive protein–DNA complexes, ensuring that these ‘forbidden’ reactions are extremely slow. The model is in good agreement with the observed in vitro kinetics of recombination by ϕC31 integrase, and defines core features of the system necessary and sufficient for directionality.

The atypical protein arginine methyltrasferase of Entamoeba histolytica (EhPRMTA) is involved in cell proliferation, heat shock response and in vitro virulence

2021 ◽  
Vol 222 ◽  
pp. 108077
Author(s):  
Christian Medina-Gómez ◽  
Jeni Bolaños ◽  
Jessica Borbolla-Vázquez ◽  
Susana Munguía-Robledo ◽  
Esther Orozco ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Heat Shock ◽  
Entamoeba Histolytica ◽  
Heat Shock Response ◽  
Shock Response

Double and single exponential kinetics of microtubule assembly in vitro

1986 ◽  
Vol 18 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Vera Gal ◽  
Divna Trajković ◽  
Dušan Ristanović
Keyword(s):  
Microtubule Assembly ◽  
Kinetics Of ◽  
Single Exponential

The Heat-Shock Response and Expression of Heat-Shock Proteins in Wheat Under Diurnal Heat Stress and Field Conditions

1994 ◽  
Vol 21 (6) ◽  
pp. 857 ◽  
Author(s):  
HT Nguyen ◽  
CP Joshi ◽  
N Klueva ◽  
J Weng ◽  
KL Hendershot ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Tolerance ◽  
Heat Shock Response ◽  
Field Conditions ◽  
Shock Response ◽  
Heat Tolerant ◽  
Shock Proteins

The occurrence of heat-shock proteins (HSPs) in response to high temperature stress is a universal phenomenon in higher plants and has been well documented. However, in agriculturally important species, less is known about the expression of HSPs under natural environments. A review of the heat-shock response in wheat (Triticum aestivum L.) is presented and recent results on the expression of wheat HSPs under diurnal stress and field conditions are reported. In the field experiment, flag leaf blade temperatures were obtained and leaf blades collected for northern blot analysis using HSP 16.9 cDNA as a probe. Temperatures of leaf blades ranged from 32 to 35�C under the tested field conditions at New Deal near Lubbock, Texas. Messenger RNAs encoding a major class of low molecular weight HSPs, HSP 16.9, were detected in all wheat genotypes examined. The results suggested that HSPs are synthesised in response to heat stress under agricultural production, and furthermore, that HSPs are produced in wheats differing in geographic background. In the controlled growth chamber experiment, HSP expression in two wheat cultivars, Mustang (heat tolerant) and Sturdy (heat susceptible) were analysed to determine if wheat genotypes differing in heat tolerance differ in in vitro HSP synthesis (translatable HSP mRNAs) under a chronic, diurnal heat-stress regime. Leaf tissues were collected from seedlings over a time-course and poly (A)+RNAs were isolated for in vitro translation and 2-D gel electrophoresis. The protein profiles shown in the 2-D gel analysis revealed that there were not only quantitative differences of individual HSPs between these two wheat lines, but also some unique HSPs which were only found in the heat tolerant line. This data provides evidence of a correlation between HSP synthesis and heat tolerance in wheat under a simulated field environment and suggests that further genetic analysis of HSPs in a segregating population is worthy of investigation. In conclusion, the results of this study provide an impetus for the investigation of the roles of HSP genes in heat tolerance in wheat.

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