Complete sequence and expression of a cDNA encoding a chicken 115-kDa melanosomal matrix protein.
A full-length cDNA clone encoding a 115-kDa melanosomal matrix protein (MMP115) was isolated from a cDNA library constructed from poly(A)+ RNA of the chicken pigmented epithelial cells. Sequence analysis showed that the cDNA encoded a polypeptide of 762 amino acids, including a hydrophobic signal peptide. There are no membrane-spanning regions, but there are five N-linked glycosylation signals. A cysteine- and histidine-rich domain is present near the C-terminus. A sequence of 24 amino acids is repeated three times in the polypeptide. A database search for homologies yielded no sequence similarities in other proteins. A plasmid containing the full-length cDNA was transferred into mouse cell lines by transfection. The transfected cells produced a protein that had the same size, 115 kDa, as the mature MMP115. When B16 mouse melanoma cells were transfected, the chicken MMP115 was expressed in the melanosomes. The presence of a specific sorting signal was suggested for localization of melanosomal proteins. Southern blot analysis has revealed that the homologues of the chicken MMP115 gene are found in many vertebrate genomes.
Mochii
M
M
Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan.
Agata
K
K
Eguchi
G
G
D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins; D001483:Base Sequence; D002454:Cell Differentiation / Q000235:genetics; D002645:Chickens; D006801:Humans; D015151:Immunoblotting; D008544:Melanocytes / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000378:metabolism*; D010957:Plasmids; D011506:Proteins / Q000235:genetics* / Q000302:isolation & purification; D015183:Restriction Mapping; D012455:Salamandridae / Q000235:genetics; D014162:Transfection; D014981:Xenopus / Q000235:genetics
D030161:Avian Proteins; D011506:Proteins; C071193:MMP115 protein, Gallus gallus