Cellular adhesion of primary Sertoli cells affects responsiveness of the extracellular signal-regulated kinases 1 and 2 to follicle-stimulating hormone but not to epidermal growth factor.
The cellular adhesion status and the exposure to soluble growth factors both contribute to mitogen-activated protein (MAP) kinase activation. To date, however, whether mitogens acting through G-protein-coupled receptors (GPCRs) need cell adhesion to activate MAP kinases/extracellular signal-regulated kinases (ERK) 1, 2 has been poorly investigated. We addressed this point in primary cultures of Sertoli cells experimentally maintained in suspension, considering that follicle-stimulating hormone (FSH) activates ERK1, 2 in attached Sertoli cells by acting through a GPCR. We found that FSH actively repressed ERK1, 2, in a cAMP-dependent but cAMP-dependent protein kinase (PKA)-independent manner, and this inhibition required the activity of a tyrosine phosphatase. In comparison, in the absence of anchorage, ERK1, 2 were still activated by epidermal growth factor, in a PKA-dependent manner. Altogether, these data suggest that sensitivity of the MAP kinase response toward cell adhesion may depend, at least in part, on the class of receptor, GPCR or receptor with tyrosine kinase activity, by which it is triggered.
Crépieux
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P
Laboratoire de Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique/CNRS/Université de Tours, UMR 6073, Centre de Recherches de Tours, Nouzilly, France. crepieux@tours.inra.fr
Martinat
N
N
Marion
S
S
Guillou
F
F
Reiter
E
E
D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D004789:Enzyme Activation; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D011962:Receptors, FSH / Q000378:metabolism; D012708:Sertoli Cells / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
D011962:Receptors, FSH; D004815:Epidermal Growth Factor; D005640:Follicle Stimulating Hormone; D066246:ErbB Receptors; D020794:Receptor Protein-Tyrosine Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases