Characteristics and kinetics of proopiomelanocortin mRNA expression by human leucocytes.
Northern blot analysis of total and poly(A)+ RNA demonstrated that human leucocytes contain several proopiomelanocortin (POMC) mRNA species, including 0.8-, 1.2-, 1.5-, and 9.5-kb transcripts. Peripheral blood lymphocytes (PBL) were found to express all four species. The other cell types had either the 0.8-kb species alone or both 0.8- and 9.5-kb species. Neutrophils were the only cells to express the 9.5-kb transcript alone. In T cell clones, both interleukin (IL)-2 alone or the antigen for which the clone was specific induced POMC accumulation within 18-24 h. Cytoplasmic dot blot analysis of PBL RNA demonstrated that POMC expression could be induced by corticotrophin releasing factor, rIL-1, and phorbol ester, but not by calcium ionophore (A23187). In PBL activated in a mixed lymphocyte culture there was increased expression, particularly of the smaller species (0.8, 1.2, and 1.5 kb), within 1-3 days of activation. The intensity of the bands began to decline thereafter. The 9.5-kb POMC transcript essentially disappeared by Day 3.
Neuroendocrinology Unit, Charing Cross and Westminster Medical School, Charing Cross Hospital, London, England.
A
A
Stephanou
P
P
Fitzharris
R A
RA
Knight
S L
SL
Lightman
D015152:Blotting, Northern; D000001:Calcimycin / Q000494:pharmacology; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D007962:Leukocytes / Q000378:metabolism*; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets / Q000187:drug effects / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism; D011061:Poly A / Q000096:biosynthesis*; D011333:Pro-Opiomelanocortin / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007375:Interleukin-1; D007376:Interleukin-2; D012333:RNA, Messenger; D011061:Poly A; D000001:Calcimycin; D011333:Pro-Opiomelanocortin; D003346:Corticotropin-Releasing Hormone; D013755:Tetradecanoylphorbol Acetate