Analogs of α-melanocyte stimulating hormone with high agonist potency and selectivity at human melanocortin receptor 1b: The role of Trp9 in molecular recognition

Biopolymers ◽  
2008 ◽  
Vol 89 (5) ◽  
pp. 401-408 ◽  
Author(s):  
Maria A. Bednarek ◽  
Tanya MacNeil ◽  
Rui Tang ◽  
Tung M. Fong ◽  
M. Angeles Cabello ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Melanocortin Receptor ◽  
Melanocyte Stimulating Hormone ◽  
Stimulating Hormone

scholarly journals Role of tyrosine kinase and protein kinase C in the steroidogenic actions of angiotensin II, α-melanocyte-stimulating hormone and corticotropin in the rat adrenal cortex

1995 ◽  
Vol 305 (2) ◽  
pp. 433-438 ◽  
Author(s):  
S Kapas ◽  
A Purbrick ◽  
J P Hinson
Keyword(s):  
Protein Kinase C ◽  
Angiotensin Ii ◽  
Protein Kinase ◽  
Tyrosine Kinase ◽  
Zona Glomerulosa ◽  
Aldosterone Secretion ◽  
Melanocyte Stimulating Hormone ◽  
Kinase C ◽  
Stimulating Hormone

The role of protein kinases in the steroidogenic actions of alpha-melanocyte-stimulating hormone (alpha-MSH), angiotensin II (AngII) and corticotropin (ACTH) in the rat adrenal zona glomerulosa was examined. Ro31-8220, a potent selective inhibitor of protein kinase C (PKC), inhibited both AngII- and alpha-MSH-stimulated aldosterone secretion but had no effect on aldosterone secretion in response to ACTH. The effect of Ro31-8220 on PKC activity was measured in subcellular fractions. Basal PKC activity was higher in cytosol than in membrane or nuclear fractions. Incubation of the zona glomerulosa with either alpha-MSH or AngII resulted in significant increases in PKC activity in the nuclear and cytosolic fractions and decreases in the membrane fraction. These effects were all inhibited by Ro31-8220. ACTH caused a significant increase in nuclear PKC activity only, and this was inhibited by Ro31-8220 without any significant effect on the steroidogenic response to ACTH, suggesting that PKC translocation in response to ACTH may be involved in another aspect of adrenal cellular function. Tyrosine phosphorylation has not previously been considered to be an important component of the response of adrenocortical cells to peptide hormones. Both AngII and alpha-MSH were found to activate tyrosine kinase, but ACTH had no effect, observations that have not been previously reported. Tyrphostin 23, a specific antagonist of tyrosine kinases, inhibited aldosterone secretion in response to AngII and alpha-MSH, but not ACTH. These data confirm the importance of PKC in the adrenocortical response to AngII and alpha-MSH, and, furthermore, indicate that tyrosine kinase may play a critical role in the steroidogenic actions of AngII and alpha-MSH in the rat adrenal zona glomerulosa.

Regulation of c-met expression in B16 murine melanoma cells by melanocyte stimulating hormone

1999 ◽  
Vol 112 (5) ◽  
pp. 623-630
Author(s):  
D. Rusciano ◽  
P. Lorenzoni ◽  
M.M. Burger
Keyword(s):  
Melanoma Cells ◽  
Parental Cell ◽  
Melanocortin Receptor ◽  
Parental Cell Line ◽  
Melanocyte Stimulating Hormone ◽  
Murine Melanoma ◽  
The One ◽  
Murine Melanoma Cells ◽  
Stimulating Hormone

B16 murine melanoma cells selected in vivo for enhanced liver metastatic ability (B16-LS9) show on the one hand an increased expression and constitutive activation of the proto-oncogene c-met (the receptor for hepatocyte growth factor/scatter factor), and on the other hand a more differentiated phenotype, when compared to the parental cell line, B16-F1. Following this observation, we have tried to establish whether there is a direct relationship between differentiation and c-met expression in B16 melanoma cells. Treatment of these cells with differentiating agents indicated that c-met expression was strongly induced by melanocyte stimulating hormone, while retinoic acid had almost no influence. c-met induction was triggered by engagement of the melanocortin receptor, cAMP elevation and PKA/PKC(α) activation, as respectively shown by the effects of ACTH, cAMP elevating agents and specific PK inhibitors. Regulation of c-met expression via the melanocortin receptor and cAMP raises the intriguing possibility that autocrine and/or paracrine mechanisms acting in vivo on this circuit might influence (through c-met expression and activation) the metastatic behavior of these tumor cells, which we have shown to be dependent on their c-met expression.

The role of melanocyte-stimulating hormone (MSH) receptor in bovine coat color determination

1995 ◽  
Vol 6 (9) ◽  
pp. 636-639 ◽  
Author(s):  
H. Klungland ◽  
D. I. Vage ◽  
L. Gomez-Raya ◽  
S. Adalsteinsson ◽  
S. Lien
Keyword(s):  
Coat Color ◽  
Melanocyte Stimulating Hormone ◽  
Color Determination ◽  
Stimulating Hormone
Sign in / Sign up

Export Citation Format

Share Document