Plows, Louise D., Cook, Richard T., Davies, Angela J. and Walker, Anthony J. (2006) Integrin engagement modulates the phosphorylation of focal adhesion kinase, phagocytosis, and cell spreading in molluscan defence cells. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, 1763(8), pp. 779-786. ISSN (print) 0167-4889Full text not available from this archive.
Integrins play a key role in cellular immune responses in a variety of organisms; however, knowledge of integrins and their effects on cell signalling and functional responses in molluscan defence reactions is poor. Using integrin-mediated cell adhesion kits, alphaVbeta3 and beta1 integrin-like subunits were identified on the surface of Lymnaea stagnalis haemocytes. Haemocyte binding via these integrins was found to be dependent on Ca2+/Mg2+. Western blotting with an anti-phospho (anti-active) focal adhesion kinase (FAK) antibody revealed a 120-125 kDa FAK-like protein in these cells; this protein was transiently phosphorylated upon haemocyte adhesion over 90 min, with maximal phosphorylation occurring after 30 min binding. Also, integrin engagement with the tetrapeptide Arg-Gly-Asp-Ser (RGDS) resulted in a rapid increase in phosphorylation of the FAK-like protein; however, RGDS did not affect the phosphorylation of extracellular signal-regulated kinase. Treatment of haemocytes with RGDS (2 mM) inhibited phagocytosis of E. coli bioparticles by 88%. Moreover, at this concentration, RGDS reduced cell spreading by 61%; stress fiber formation was also impaired. Taken together, these results demonstrate a role for integrins in L. stagnalis haemocyte adhesion and defence reactions and, for the first time, link integrin engagement to FAK activation in molluscs.
|Uncontrolled Keywords:||mollusc, invertebrate defence, haemocytes, FAK, ERK, RGDS|
|Research Area:||Allied health professions and studies|
|Faculty, School or Research Centre:||Faculty of Science (until 2011) > School of Pharmacy and Chemistry|
|Depositing User:||Sara Burnett|
|Date Deposited:||27 Jun 2007|
|Last Modified:||30 Sep 2010 10:49|
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