Thyrotropin-releasing activity of histone H2A, H2B and peptide MB35.
Histones possess multiple hormone-like activities. We studied the specificity and signal transduction pathways involved in the thyrotrophin (TSH)-releasing activity of histones H2A, H2B and peptide MB35, a H2A fragment, using perifused and incubated dispersed rat pituitary cells and measuring TSH release by a specific R1A. Histones released TSH in a dose- and time-dependent fashion while peptide MB35 behaved as a weaker secretagogue. Trifluoperazine and EGTA blocked histone-stimulated TSH release while forskolin and other cAMP enhancers did not. We conclude that the TSH-releasing activity of histones H2A and H2B is mediated by calcium- and diacylglycerol-associated pathways.
Brown
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INIBIOLP, School of Medicine, National University of La Plata, Argentina.
Sosa
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Goya
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D000704:Analysis of Variance; D000818:Animals; D004347:Drug Interactions; D005260:Female; D006657:Histones / Q000737:chemistry / Q000494:pharmacology*; D066298:In Vitro Techniques; D010446:Peptide Fragments / Q000494:pharmacology*; D010477:Perfusion; D010903:Pituitary Gland, Anterior / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012636:Secretory Rate / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013972:Thyrotropin / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology
D006657:Histones; D010446:Peptide Fragments; D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin