ACTH induces c-fos proto-oncogene in fibroblasts expressing the ACTH receptor.
The entire ACTH receptor (ACTH-R) cDNA was amplified by RT/PCR from mouse Y-1 adrenocortical cells, subcloned into the pMOSBlue T vector, sequenced and inserted into the pSVK3 mammalian vector to obtain pSVACTHR. Balb 3T3 fibroblasts were co-transfected with pSVACTHR plus pSV2-neo and the transfectants were selected with G418 and cloned. Genomic integration of pSVACTHR and transcription of ACTH-R cDNA were checked by Southern blot and RT/PCR respectively. Expression of active ACTH-R protein was tested by measuring cAMP production in response to ACTH. Two ACTH-R expressing transfectants (clones 03 and 07) increased cAMP accumulation in response to ACTH. They were morphologically identical to parental 3T3 cells, but required 10-20% FCS to grow. In these transfectants, ACTH induced c-FOS protein expression, but did not activate the ERK isoforms of MAP Kinase and did not stimulate DNA synthesis. Apparently, the ACTH-R in Balb 3T3 cells induces the c-fos gene by a pathway independent of cAMP/protein kinase A and ERK/MAP Kinase.
Forti
F L
FL
Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Brasil.
Armelin
H A
HA
D016475:3T3 Cells; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis; D005347:Fibroblasts / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology*; D051379:Mice; D010766:Phosphorylation / Q000187:drug effects; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics*; D011519:Proto-Oncogenes / Q000235:genetics*; D018043:Receptors, Corticotropin / Q000378:metabolism*; D014162:Transfection / Q000502:physiology
D016760:Proto-Oncogene Proteins c-fos; D018043:Receptors, Corticotropin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D003994:Bucladesine; D000324:Adrenocorticotropic Hormone; D004247:DNA; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D000262:Adenylyl Cyclases