Expression of gene coding for a melanosomal matrix protein transcriptionally regulated in the transdifferentiation of chick embryo pigmented epithelial cells.
Chicken 115-kDa melanosomal matrix protein (MMP115) was purified from cultured pigmented epithelial cells (PECs), and mouse antiserum was raised to isolate cDNA clones. lambda gt11 expression library made from poly(A)+ RNA of the homogeneous population of PECs was screened with the antiserum. Nine positive clones were obtained from 5 X 10(5) independent phages, and inserts of them shared a common nucleotide sequence. The beta-galactosidase fusion protein from the longest insert (MM-2, 1.0 kb long) was recognized by the anti-MMP115 antiserum in immunoblotting, and the antibody, which was affinity-selected by the fusion protein, specifically reacted with the 115-kDa protein in PEC extracts. The RNA blot analysis with the MM-2 insert as a probe revealed that a transcript of 2.6 kb was expressed by the PEC in a tissue-specific manner. mRNA expressions in the process of in vitro transdifferentiation from PECs to lens cells were analyzed using the MM-2 insert. The transcripts were detected in neither transdifferentiating, transdifferentiated lens cells nor bipotent dedifferentiated PECs, although the 2.6 kb transcript was vigorously synthesized by redifferentiating into PECs.
Mochii
M
M
Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan.
Agata
K
K
Kobayashi
H
H
Yamamoto
T S
TS
Eguchi
G
G
D000818:Animals; D002454:Cell Differentiation; D002642:Chick Embryo; D004247:DNA / Q000032:analysis; D007908:Lens, Crystalline / Q000166:cytology* / Q000378:metabolism; D008544:Melanocytes / Q000166:cytology* / Q000378:metabolism; D010857:Pigment Epithelium of Eye / Q000166:cytology* / Q000378:metabolism; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic
D011506:Proteins; D012333:RNA, Messenger; D004247:DNA