The number of receptors for beta-melanocyte stimulating hormone in Cloudman melanoma cells is increased by dibutyryl adenosine 3':5'-cyclic monophosphate or cholera toxin.

Abstract

Cultured Cloudman melanoma cells exposed either to dibutyryI 3':5'-cyclic AMP and theophylline or to cholera toxin bind significantly more 'MI-labeled ,Bmelanocyte stimulating hormone (MSH) and fluorescein-abeled MSH than untreated cells. MSH

Biological activity, binding, and metabolic fate of Ac‐[Nle4, D‐Phe7]α‐MSH4–11NH2 with the F1 variant of B16 melanoma cells

“…This would imply that there are at most 15,000 receptors er cell. This is similar to the number of receptors for 5I beta-MSH and an a-MSH-ferritin-FITC conjugate in Cloudman melanoma cells (Di Pasquale et al, 1977.…”

“…Beta-MSH is a peptide with 18 amino acids. Di Pasquale et al (1977) demonstrated the presence of receptors for (lZ5I) beta-MSH on Cloudman melanoma cells.…”

Regulation of bradykinin receptor level by cholera toxin, pertussis toxin and forskolin in cultured human fibroblasts

“…Recently, transformation of 3T3 cells with Kirsten murine sarcoma virus (Parries et al, 1987), overexpression in Rat-1 cells of normal or transforming forms of Ha-, Ki-and N-ras proteins (Downward et al, 1988), and differentiation of PC12 cells with nerve growth factor (Volonte et al, 1988) (Thomopoulos et al, 1977), f,-melanocyte stimulating hormone (DiPasquale et al, 1977), interleukin-2 (Narumiya et al, 1987), and low-density lipoprotein (Golos & Strauss, 1985). In the latter two cases, transcription of the receptor genes was stimulated by elevated cyclic AMP levels (Narumiya et al, 1987;Golos & Strauss, 1987 (1986) demonstrated that a functional kinase was required for the cyclic AMP induction of transcription of the somatostatin gene.…”

Corticotropin Releasing Hormone and Proopiomelanocortin Involvement in the Cutaneous Response to Stress

“…This G 2 phase coupling of increased MSH receptor expression is associated with increased cellular responsiveness to the ligand (40,64,234,283,449). Factors that raise intracellular cAMP levels such as dibutyryl cAMP and cholera toxin can also upregulate MSH receptor expression (95). In general, factors increasing intracellular levels of cAMP, such as MSH and ACTH, upregulate expression of their own receptors (70,71,249,291,400).…”

“…When the skin is exposed to UVR, thermal, chemical, or biological insults, it responds with enhanced production of cytokines, growth factors, ACTH, MSH, and intermediates of melanogenesis (365,378). In normal and malignant melanocytes, many cytokines such as Il-1␣, IL-1␤, endothelin-1, adult T-cell leukemia-derived factor/thioredoxin (ADF/TRX), INF-␣, INF-␤, INF-␥, dibutyryl cAMP, and the hormones ␣-MSH, ␤-MSH and ACTH can upregulate expression of the MC-1 gene and of functional cellsurface MSH receptors (31,64,67,70,71,95,119,120,175,176,400). IL-1 can also stimulate MC-1 receptor expression in normal and malignant human keratinocytes (31,64) and HDMEC (341,342).…”