scholarly journals Extracellular matrix and integrin signalling: the shape of things to come

1999 ◽  
Vol 339 (3) ◽  
pp. 481-488 ◽  
Author(s):  
Nancy J. BOUDREAU ◽  
Peter Lloyd JONES
Keyword(s):  
Extracellular Matrix ◽  
Protein Kinases ◽  
Cell Shape ◽  
Large Body ◽  
Three Dimensional ◽  
Small Gtpases ◽  
Intracellular Signalling ◽  
Receptor Protein ◽  
Stringent Requirement ◽  
Mitogen Activated Protein

The extracellular matrix (ECM) and integrins collaborate to regulate gene expression associated with cell growth, differentiation and survival. Biochemical and molecular analyses of integrin signalling pathways have uncovered several critical cytoplasmic proteins that link the ECM and integrins to intracellular pathways that may contribute to anchorage-dependent growth. A large body of evidence now indicates that the non-receptor protein kinases focal adhesion kinase (FAK) and specific members of the mitogen-activated protein kinases (MAPKs), including the extracellular-signal-regulated kinases (ERKs), mediate these ECM- and integrin-derived signalling events. However, little is known about how FAK and MAPKs contribute to biological processes other than cell proliferation or migration. In addition, remarkably little is known concerning the signalling events that occur in cells that adhere to complex multivalent extracellular matrices via multiple integrin receptors. Given the stringent requirement for attaining a proper morphology in ECM/integrin-directed cell behaviour, it is still not clear how cell shape and tissue architecture impact upon intracellular signalling programmes involving FAK and MAPKs. However, the recent discovery that members of the Rho family of small GTPases are able to regulate ECM/integrin pathways that modulate both cell shape and intracellular signalling provides new insights into how cell morphology and signal transduction become integrated, especially within three-dimensional differentiated tissues.

scholarly journals Comprehensive Phosphoproteomic Analysis of Pepper Fruit Development Provides Insight into Plant Signaling Transduction

2020 ◽  
Vol 21 (6) ◽  
pp. 1962 ◽  
Author(s):  
Zhoubin Liu ◽  
Junheng Lv ◽  
Yuhua Liu ◽  
Jing Wang ◽  
Zhuqing Zhang ◽  
...  
Keyword(s):  
Protein Kinases ◽  
Fruit Development ◽  
Development Stage ◽  
Receptor Protein ◽  
Plant Signaling ◽  
Signaling Transduction ◽  
Calcium Dependent ◽  
Pepper Fruit ◽  
Mitogen Activated Protein ◽  
Dependent Protein

Limited knowledge is available for phosphorylation modifications in pepper (Capsicum annuum L.), especially in pepper fruit development. In this study, we conducted the first comprehensive phosphoproteomic analysis of pepper fruit at four development stage by Tandem Mass Tag proteomic approaches. A total of 2639 unique phosphopeptides spanning 1566 proteins with 4150 nonredundant sites of phosphorylation were identified, among which 2327 peptides in 1413 proteins were accurately quantified at four different stages. Mature Green (MG) to breaker stage showed the largest number of differentially expressed phosphoproteins and the number of downregulated phosphoproteins was significantly higher than that of upregulated after MG stage. Twenty seven phosphorylation motifs, including 22 pSer motifs and five pThr motifs and 85 kinase including 28 serine/threonine kinases, 14 receptor protein kinases, six mitogen-activated protein kinases, seven calcium-dependent protein kinases, two casein kinases, and some other kinases were quantified. Then the dynamic changes of phosphorylated proteins in ethylene and abscisic acid signaling transduction pathways during fruit development were analyzed. Our results provide a cascade of phosphoproteins and a regulatory network of phosphorylation signals, which help to further understand the mechanism of phosphorylation in pepper fruit development.

scholarly journals Microtubules regulate GEF-H1 in response to extracellular matrix stiffness

2012 ◽  
Vol 23 (13) ◽  
pp. 2583-2592 ◽  
Author(s):  
Jessica N. Heck ◽  
Suzanne M. Ponik ◽  
Maria G. Garcia-Mendoza ◽  
Carolyn A. Pehlke ◽  
David R. Inman ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Three Dimensional ◽  
Mitogen Activated Protein Kinase ◽  
The Novel ◽  
Matrix Stiffness ◽  
Rhoa Activity ◽  
Microtubule Stability ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Extracellular Matrix Stiffness

Breast epithelial cells sense the stiffness of the extracellular matrix through Rho-mediated contractility. In turn, matrix stiffness regulates RhoA activity. However, the upstream signaling mechanisms are poorly defined. Here we demonstrate that the Rho exchange factor GEF-H1 mediates RhoA activation in response to extracellular matrix stiffness. We demonstrate the novel finding that microtubule stability is diminished by a stiff three-dimensional (3D) extracellular matrix, which leads to the activation of GEF-H1. Surprisingly, activation of the mitogen-activated protein kinase kinase/extracellular signal-regulated kinase pathway did not contribute to stiffness-induced GEF-H1 activation. Loss of GEF-H1 decreases cell contraction of and invasion through 3D matrices. These data support a model in which matrix stiffness regulates RhoA through microtubule destabilization and the subsequent release and activation of GEF-H1.

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