In situ localization of agouti signal protein in murine skin using immunohistochemistry with an ASP-specific antibody.
Switching between production of eumelanin or pheomelanin in follicular melanocytes is responsible for hair color in mammals; in mice, this switch is controlled by the agouti locus, which encodes agouti signal protein (ASP) through the action of melanocortin receptor 1. To study expression and processing patterns of ASP in the skin and its regulation of pigment production in hair follicles, we have generated a rabbit antibody (termed alphaPEP16) against a synthetic peptide that corresponds to the carboxyl terminus of ASP. The specificity of that antibody was measured by ELISA and was confirmed by Western blot analysis. Using immunohistochemistry, we characterized the expression of ASP in the skin of newborn mice at 3, 6, and 9 days postnatally. Expression in nonagouti (a/a) black mouse skin was negative at all times examined, as expected, and high expression of ASP was observed in 6 day newborn agouti (A/+) and in 6 and 9 day newborn lethal yellow (A(y)/a) mouse skin. In lethal yellow (pheomelanogenic) mice, ASP expression increased day by day as the hair color became more yellow. These expression patterns suggest that ASP is delivered quickly and efficiently to melanocytes and to hair matrix cells in the hair bulbs where it regulates melanin production.
Matsunaga
N
N
Pigment Cell Biology Section, Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Virador
V
V
Santis
C
C
Vieira
W D
WD
Furumura
M
M
Matsunaga
J
J
Kobayashi
N
N
Hearing
V J
VJ
D054366:Agouti Signaling Protein; D000818:Animals; D000918:Antibody Specificity; D005455:Fluorescent Antibody Technique; D006200:Hair Color / Q000502:physiology*; D018859:Hair Follicle / Q000648:ultrastructure*; D036341:Intercellular Signaling Peptides and Proteins; D008543:Melanins / Q000096:biosynthesis; D009074:Melanocyte-Stimulating Hormones / Q000037:antagonists & inhibitors; D008544:Melanocytes / Q000648:ultrastructure*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D014442:Monophenol Monooxygenase / Q000302:isolation & purification; D011506:Proteins / Q000276:immunology / Q000302:isolation & purification*; D018043:Receptors, Corticotropin; D044101:Receptors, Melanocortin
D054366:Agouti Signaling Protein; D036341:Intercellular Signaling Peptides and Proteins; D008543:Melanins; D011506:Proteins; D018043:Receptors, Corticotropin; D044101:Receptors, Melanocortin; C016042:phaeomelanin; C041877:eumelanin; D009074:Melanocyte-Stimulating Hormones; D014442:Monophenol Monooxygenase