scholarly journals Focal Adhesion Kinases in Adhesion Structures and Disease

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Pierre P. Eleniste ◽  
Angela Bruzzaniti

Cell adhesion to the extracellular matrix (ECM) is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organization and role of focal adhesions, podosomes, and invadopodia in different cells. In addition, we discuss the role of the tyrosine kinases, FAK, Pyk2, and Src, which are critical for the function of the different adhesion structures. Finally, we discuss the essential role of these tyrosine kinases from the perspective of human diseases.

2012 ◽  
Vol 196 (3) ◽  
pp. 363-374 ◽  
Author(s):  
Patrick W. Oakes ◽  
Yvonne Beckham ◽  
Jonathan Stricker ◽  
Margaret L. Gardel

Focal adhesion composition and size are modulated in a myosin II–dependent maturation process that controls adhesion, migration, and matrix remodeling. As myosin II activity drives stress fiber assembly and enhanced tension at adhesions simultaneously, the extent to which adhesion maturation is driven by tension or altered actin architecture is unknown. We show that perturbations to formin and α-actinin 1 activity selectively inhibited stress fiber assembly at adhesions but retained a contractile lamella that generated large tension on adhesions. Despite relatively unperturbed adhesion dynamics and force transmission, impaired stress fiber assembly impeded focal adhesion compositional maturation and fibronectin remodeling. Finally, we show that compositional maturation of focal adhesions could occur even when myosin II–dependent cellular tension was reduced by 80%. We propose that stress fiber assembly at the adhesion site serves as a structural template that facilitates adhesion maturation over a wide range of tensions. This work identifies the essential role of lamellar actin architecture in adhesion maturation.


Author(s):  
Mohamed Salama ◽  
Cakil Angew ◽  
Gregory Fantham

This chapter falls in two parts. Part 1 discusses team issues with emphasis on virtual teams. The first few sections briefly compare and contrast the different types of team and how team performance should be planned and managed, in line with set goals and detailed deliverables. This will cover a wide range of concepts that come into play under performance management and measurement. The following sections focus on the challenges that virtual teams face amid the prevailing digital transformation and suggest effective measures to address those challenges. The presented concepts are generic, thus can be readily applied to the context of event management. Part 2 comprises two sections; the first discusses well-being and cross-cultural variations in relation to event management, while the second section is focused on the role of social psychology in devising event experiences.


2020 ◽  
Vol 15 ◽  
pp. 263310552097541
Author(s):  
Kolter B Grigsby ◽  
Antonia M Savarese ◽  
Pamela Metten ◽  
Barbara J Mason ◽  
Yuri A Blednov ◽  
...  

High Drinking in the Dark (HDID-1) mice represent a unique genetic risk model of binge-like drinking and a novel means of screening potential pharmacotherapies to treat alcohol use disorders (AUDs). We tested the effects of tacrolimus (0, 0.5, 1, and 2 mg/kg), sirolimus (0, 5, 10, and 20 mg/kg), palmitoylethanolamide (PEA; 0, 75, 150, and 225 mg/kg), and secukinumab (0, 5, 20, and 60 mg/kg) on binge-like ethanol intake (2-day, “Drinking in the Dark” [DID]) and blood alcohol levels (BALs) in HDID-1 mice. Tacrolimus reduced ethanol intake and BALs. Tacrolimus had no effect on water intake, but reduced saccharin intake. There was no effect of sirolimus, PEA, or secukinumab on ethanol intake or BALs. These results compare and contrast with previous work addressing these compounds or their targeted mechanisms of action on ethanol drinking, highlighting the importance of screening a wide range of models and genotypes to inform the role of neuroimmune signaling in AUDs.


1996 ◽  
Vol 271 (3) ◽  
pp. C763-C771 ◽  
Author(s):  
T. S. Chu ◽  
H. Tsuganezawa ◽  
Y. Peng ◽  
A. Cano ◽  
M. Yanagisawa ◽  
...  

Endothelin-1 (ET-1) binding to ETB receptors increases the activity of the apical membrane Na+/H+ antiporter (NHE3) of renal proximal tubule and cultured OKP cells. In OKPETB6 cells, a clonal cell line of OKP cells that overexpresses ETB receptors, ET-1-induced increases in Na+/H+ antiporter activity are mediated 50% by Ca2(+)-dependent pathways and 50% by tyrosine kinase pathways. ET-1 induces tyrosine phosphorylation of proteins of 68, 110, 125, 130, and 210 kDa. ET-1-induced tyrosine phosphorylation is mediated by the ETB receptor and is not dependent on increases in cell Ca2+ or protein kinase C. The 68-, 110-, 125-, and 130-kDa phosphoproteins are cytosolic, whereas the 210-kDa phosphoprotein is an integral membrane protein. Immunoprecipitation studies showed that the 68-kDa protein is paxillin and the 125-kDa protein is p125FAK (focal adhesion kinase). Cytochalasin D, which disrupts focal adhesions, prevented ET-1-induced tyrosine phosphorylation of paxillin, p110, p125FAK, and p130 but did not prevent tyrosine phosphorylation of p210 and did not prevent ET-1-induced increases in Na+/H+ antiporter activity. Thus 50% of ETB receptor-induced Na+/H+ antiporter activation is mediated by tyrosine kinase pathways, possibly involving p210. ETB receptor activation also induces tyrosine phosphorylation of focal adhesion proteins, but this is not required for antiporter activation.


2011 ◽  
Vol 78 (4) ◽  
Author(s):  
Amit Pathak ◽  
Robert M. McMeeking ◽  
Anthony G. Evans ◽  
Vikram S. Deshpande

Cells communicate with their external environment via focal adhesions and generate activation signals that in turn trigger the activity of the intracellular contractile machinery. These signals can be triggered by mechanical loading that gives rise to a cooperative feedback loop among signaling, focal adhesion formation, and cytoskeletal contractility, which in turn equilibrates with the applied mechanical loads. We devise a signaling model that couples stress fiber contractility and mechano-sensitive focal adhesion models to complete this above mentioned feedback loop. The signaling model is based on a biochemical pathway where IP3 molecules are generated when focal adhesions grow. These IP3 molecules diffuse through the cytosol leading to the opening of ion channels that disgorge Ca2+ from the endoplasmic reticulum leading to the activation of the actin/myosin contractile machinery. A simple numerical example is presented where a one-dimensional cell adhered to a rigid substrate is pulled at one end, and the evolution of the stress fiber activation signal, stress fiber concentrations, and focal adhesion distributions are investigated. We demonstrate that while it is sufficient to approximate the activation signal as spatially uniform due to the rapid diffusion of the IP3 through the cytosol, the level of the activation signal is sensitive to the rate of application of the mechanical loads. This suggests that ad hoc signaling models may not be able to capture the mechanical response of cells to a wide range of mechanical loading events.


2015 ◽  
Vol 308 (2) ◽  
pp. C101-C110 ◽  
Author(s):  
Line Jee Hartmann Rasmussen ◽  
Helene Steenkær Holm Müller ◽  
Bente Jørgensen ◽  
Stine Falsig Pedersen ◽  
Else Kay Hoffmann

The mechanisms linking cell volume sensing to volume regulation in mammalian cells remain incompletely understood. Here, we test the hypothesis that activation of nonreceptor tyrosine kinases Src, focal adhesion kinase (FAK), and Janus kinase-2 (Jak2) occurs after osmotic shrinkage of NIH3T3 fibroblasts and contributes to volume regulation by activation of NKCC1. FAK phosphorylation at Tyr397, Tyr576/577, and Tyr861 was increased rapidly after exposure to hypertonic (575 mOsm) saline, peaking after 10 (Tyr397, Tyr576/577) and 10–30 min (Tyr861). Shrinkage-induced Src family kinase autophosphorylation (pTyr416-Src) was induced after 2–10 min, and immunoprecipitation indicated that this reflected phosphorylation of Src itself, rather than Fyn and Yes. Phosphorylated Src and FAK partly colocalized with vinculin, a focal adhesion marker, after hypertonic shrinkage. The Src inhibitor pyrazolopyrimidine-2 (PP2, 10 μM) essentially abolished shrinkage-induced FAK phosphorylation at Tyr576/577 and Tyr861, yet not at Tyr397, and inhibited shrinkage-induced NKCC1 activity by ∼50%. The FAK inhibitor PF-573,228 augmented shrinkage-induced Src phosphorylation, and inhibited shrinkage-induced NKCC1 activity by ∼15%. The apparent role of Src in NKCC1 activation did not reflect phosphorylation of myosin light chain kinase (MLC), which was unaffected by shrinkage and by PP2, but may involve Jak2, a known target of Src, which was rapidly activated by osmotic shrinkage and inhibited by PP2. Collectively, our findings suggest a major role for Src and possibly the Jak2 axis in shrinkage-activation of NKCC1 in NIH3T3 cells, whereas no evidence was found for major roles for FAK and MLC in this process.


2009 ◽  
Vol 29 (6) ◽  
pp. 1506-1514 ◽  
Author(s):  
Cuc T. T. Bach ◽  
Sarah Creed ◽  
Jessie Zhong ◽  
Maha Mahmassani ◽  
Galina Schevzov ◽  
...  

ABSTRACT The balance of transition between distinct adhesion types contributes to the regulation of mesenchymal cell migration, and the characteristic association of adhesions with actin filaments led us to question the role of actin filament-associating proteins in the transition between adhesive states. Tropomyosin isoform association with actin filaments imparts distinct filament structures, and we have thus investigated the role for tropomyosins in determining the formation of distinct adhesion structures. Using combinations of overexpression, knockdown, and knockout approaches, we establish that Tm5NM1 preferentially stabilizes focal adhesions and drives the transition to fibrillar adhesions via stabilization of actin filaments. Moreover, our data suggest that the expression of Tm5NM1 is a critical determinant of paxillin phosphorylation, a signaling event that is necessary for focal adhesion disassembly. Thus, we propose that Tm5NM1 can regulate the feedback loop between focal adhesion disassembly and focal complex formation at the leading edge that is required for productive and directed cell movement.


2008 ◽  
Vol 82 (12) ◽  
pp. 5962-5966 ◽  
Author(s):  
Ramon Wade ◽  
Nicole Brimer ◽  
Scott Vande Pol

ABSTRACT Papillomavirus E6 proteins are adapters that change the function of cellular regulatory proteins. The bovine papillomavirus type 1 E6 (BE6) binds to LXXLL peptide sequences termed LD motifs (consensus sequence LDXLLXXL) on the cellular protein paxillin that is a substrate of Src and focal adhesion kinases. Anchorage-independent transformation induced by BE6 required both paxillin and BE6-binding LD motifs on paxillin but was independent of the major tyrosine phosphorylation sites of paxillin. The essential role of paxillin in transformation by BE6 highlights the role of paxillin in the transduction of cellular signals that result in anchorage-independent cell proliferation.


2004 ◽  
Vol 22 (2) ◽  
pp. 361-371 ◽  
Author(s):  
David W. Sternberg ◽  
D. Gary Gilliland

Human leukemias are frequently associated with the aberrant expression of activated fusion tyrosine kinases or activated protein tyrosine kinases carrying insertional or point mutations. The activated kinase enzymes typically phosphorylate one or more signal transducer and activator of transcription (STAT) factors, which translocate to the cell nucleus and regulate the expression of genes associated with survival and proliferation. The phosphorylation and activation of STAT family members has been described in a wide range of human leukemias. Furthermore, animal models of leukemia have demonstrated the pivotal contribution of STAT activation to leukemic pathogenesis. This review discusses evidence for the functional importance of STAT activation in the biology of leukemia and current opportunities for modulating STAT proteins in the therapy of this group of diseases.


Sign in / Sign up

Export Citation Format

Share Document