Decreased beta 2-adrenergic receptor mRNA expression in receptor-deficient S49 lymphoma cells.
Many variants of the S49 mouse lymphoma cell have been isolated along the pathway of cyclic AMP generation and response. Two such variants, beta p and beta d, were isolated by Johnson and colleagues and described in 1979 [Mol. Pharmacol. 15:16-27 (1979)]. The beta p and beta d variants express one half and one quarter, respectively, of the wild-type number of beta 2-adrenergic receptors. This observation has now been extended through the use of DNA-excess solution hybridization. Using this exquisitely sensitive technique for quantitation of gene and mRNA, we have been able to demonstrate that the beta 2-adrenergic receptor-deficient variant cells contain the same quantity of the beta 2-adrenergic receptor gene as the wild-type cells. In contrast, the beta 2-adrenergic receptor-deficient variant cells express reduced quantities of beta 2-adrenergic receptor-specific mRNA. The amount of beta 2-adrenergic receptor-specific mRNA correlates very well with the reduction in receptor expression in these cells. Both gene and mRNA in the wild-type and variant cells appear to be the same size, as judged by Southern and Northern analysis. Thus, the diminution of beta 2-adrenergic receptors in the beta p and beta d variants appears to reflect primarily the relative paucity of gene transcripts in the variant cells. These data imply that variations in cellular content of beta 2-adrenergic receptor mRNA, which may occur among closely related cells, is one explanation for differences in receptor number.
Hughes
R J
RJ
Department of Pharmacology, University of California, San Diego, La Jolla 92093-0636.
Howard
M J
MJ
Allen
J M
JM
Insel
P A
PA
D000818:Animals; D001483:Base Sequence; D015870:Gene Expression / Q000235:genetics; D008223:Lymphoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008969:Molecular Sequence Data; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000235:genetics* / Q000502:physiology; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D011943:Receptors, Adrenergic, beta