scholarly journals Distinct roles for Crk adaptor isoforms in actin reorganization induced by extracellular signals

2009 ◽  
Vol 122 (22) ◽  
pp. 4228-4238 ◽  
Author(s):  
S. Antoku ◽  
B. J. Mayer
Keyword(s):  
Actin Reorganization ◽  
Extracellular Signals

scholarly journals The Campylobacter jejuni CiaD effector co-opts the host cell protein IQGAP1 to promote cell entry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nicholas M. Negretti ◽  
Christopher R. Gourley ◽  
Prabhat K. Talukdar ◽  
Geremy Clair ◽  
Courtney M. Klappenbach ◽  
...  
Keyword(s):  
Host Cell ◽  
Campylobacter Jejuni ◽  
Foodborne Pathogen ◽  
Small Gtpase ◽  
Host Cells ◽  
Cell Protein ◽  
Host Cell Protein ◽  
Cell Binding ◽  
Actin Reorganization ◽  
Cell Cytosol

AbstractCampylobacter jejuni is a foodborne pathogen that binds to and invades the epithelial cells lining the human intestinal tract. Maximal invasion of host cells by C. jejuni requires cell binding as well as delivery of the Cia proteins (Campylobacter invasion antigens) to the host cell cytosol via the flagellum. Here, we show that CiaD binds to the host cell protein IQGAP1 (a Ras GTPase-activating-like protein), thus displacing RacGAP1 from the IQGAP1 complex. This, in turn, leads to the unconstrained activity of the small GTPase Rac1, which is known to have roles in actin reorganization and internalization of C. jejuni. Our results represent the identification of a host cell protein targeted by a flagellar secreted effector protein and demonstrate that C. jejuni-stimulated Rac signaling is dependent on IQGAP1.

The complex network of mTOR signalling in the heart

2021 ◽  
Author(s):  
Sebastiano Sciarretta ◽  
Maurizio Forte ◽  
Giacomo Frati ◽  
Junichi Sadoshima
Keyword(s):  
Cardiovascular System ◽  
Cardiac Development ◽  
Metabolic Stress ◽  
Pressure Overload ◽  
Current Data ◽  
Loss Of Function ◽  
Extracellular Signals ◽  
Mtorc1 Activation ◽  
Mtor Modulation ◽  
Mtor Signalling

Abstract The mechanistic target of rapamycin (mTOR) integrates several intracellular and extracellular signals involved in the regulation of anabolic and catabolic processes. mTOR assembles into two macromolecular complexes, named mTORC1 and mTORC2, which have different regulators, substrates and functions. Studies of gain- and loss-of-function animal models of mTOR signalling revealed that mTORC1/2 elicits both adaptive and maladaptive functions in the cardiovascular system. Both mTORC1 and mTORC2 are indispensable for driving cardiac development and cardiac adaption to stress, such as pressure overload. However, persistent and deregulated mTORC1 activation in the heart is detrimental during stress and contributes to the development and progression of cardiac remodelling and genetic and metabolic cardiomyopathies. In this review, we discuss the latest findings regarding the role of mTOR in the cardiovascular system, both under basal conditions and during stress, such as pressure overload, ischemia, and metabolic stress. Current data suggest that mTOR modulation may represent a potential therapeutic strategy for the treatment of cardiac diseases.

scholarly journals Mechanical Point Loading Induces Cortex Stiffening and Actin Reorganization

2019 ◽  
Vol 117 (8) ◽  
pp. 1405-1418 ◽  
Author(s):  
Jinrong Hu ◽  
Shenbao Chen ◽  
Wenhui Hu ◽  
Shouqin Lü ◽  
Mian Long
Keyword(s):  
Actin Reorganization

Neurotrophins Require Distinct Extracellular Signals to Promote the Survival of CNS Neurons in Vitro

2000 ◽  
Vol 165 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Barbara Franke ◽  
Nadhim Bayatti ◽  
Jürgen Engele
Keyword(s):  
Extracellular Signals ◽  
Cns Neurons

scholarly journals Targeting of p38 Mitogen-Activated Protein Kinases to MEF2 Transcription Factors

1999 ◽  
Vol 19 (6) ◽  
pp. 4028-4038 ◽  
Author(s):  
Shen-Hsi Yang ◽  
Alex Galanis ◽  
Andrew D. Sharrocks
Keyword(s):  
Transcription Factors ◽  
Transcriptional Activation ◽  
Cellular Response ◽  
Map Kinases ◽  
Biological Response ◽  
Extracellular Signals ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT Mitogen-activated protein (MAP) kinase-mediated signalling to the nucleus is an important event in the conversion of extracellular signals into a cellular response. However, the existence of multiple MAP kinases which phosphorylate similar phosphoacceptor motifs poses a problem in maintaining substrate specificity and hence the correct biological response. Both the extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) subfamilies of MAP kinases use a second specificity determinant and require docking to their transcription factor substrates to achieve maximal substrate activation. In this study, we demonstrate that among the different MAP kinases, the MADS-box transcription factors MEF2A and MEF2C are preferentially phosphorylated and activated by the p38 subfamily members p38α and p38β2. The efficiency of phosphorylation in vitro and transcriptional activation in vivo of MEF2A and MEF2C by these p38 subtypes requires the presence of a kinase docking domain (D-domain). Furthermore, the D-domain from MEF2A is sufficient to confer p38 responsiveness on different transcription factors, and reciprocal effects are observed upon the introduction of alternative D-domains into MEF2A. These results therefore contribute to our understanding of signalling to MEF2 transcription factors and demonstrate that the requirement for substrate binding by MAP kinases is an important facet of three different subclasses of MAP kinases (ERK, JNK, and p38).

A Fluorescence Polarization Assay for Cyclic Nucleotide Phosphodiesterases

2002 ◽  
Vol 7 (3) ◽  
pp. 215-222 ◽  
Author(s):  
Wei Huang ◽  
Yan Zhang ◽  
J. Richard Sportsman
Keyword(s):  
Cyclic Nucleotide ◽  
Fluorescence Polarization ◽  
Drug Targets ◽  
Second Messengers ◽  
Reaction Products ◽  
Cyclic Nucleotide Phosphodiesterases ◽  
Extracellular Signals ◽  
Fluorescence Polarization Assay ◽  
Hydrolysis Of ◽  
Nucleotide Phosphodiesterases

Cyclic nucleotide phosphodiesterases (PDEs) catalyze the hydrolysis of the 3′-ester bond of cyclic AMP (cAMP) and cyclic GMP (cGMP), important second messengers in the transduction of a variety of extracellular signals. There is growing interest in the study of PDEs as drug targets for novel therapeutics. We describe the development of a homogeneous fluorescence polarization assay for PDEs based on the strong binding of PDE reaction products (i.e., AMP or GMP) onto modified nanoparticles through interactions with immobilized trivalent metal cations. This assay technology (IMAP) is applicable to both cAMP- and cGMP-specific PDEs. Results of the assay in 384- and 1536-well microplates are presented.

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