Structure and lens expression of the gene encoding chicken beta A3/A1-crystallin.
The beta A1- and beta A3-crystallins are major polypeptides in the lenses of vertebrates. We present evidence that a single beta A3/A1 gene encodes these two proteins in the chicken. The beta A3/A1 gene has been sequenced and its functional promoter identified in transfection experiments. The chicken beta A3/A1 gene has the same structure as the human orthologue: six exons with standard splice sites and two alternative start codons from which the protein products are apparently translated. Northern analysis revealed an abundant 0.9-kb transcript in the lenses of 1-2-day-old chickens and no detectable transcripts in the rest of the eye, brain, heart, kidney, liver or skeletal muscle. The 5'-flanking sequence of the chicken beta A3/A1 gene is very similar to that of the human and mouse genes, suggesting conservation of important putative regulatory sequences in addition to the TATA box. A thymidine-rich element (bp -218 to -163) and a potential AP-1-binding site (bp -264 to -258) are present within the chicken 5'-flanking region. A DNA fragment from -382 to +22 of the chicken beta A3/A1 gene is sufficient to promote expression of the bacterial cat gene in transfected chicken primary lens epithelial cells, but not in transfected dermal fibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS)
McDermott
J B
JB
Laboratory of Molecular and Developmental Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892.
Peterson
C A
CA
Piatigorsky
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002642:Chick Embryo; D003459:Crystallins / Q000737:chemistry / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics; D007908:Lens, Crystalline / Q000378:metabolism*; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics; D038205:beta-Crystallin A Chain
C489108:CRYBA1 protein, human; D003459:Crystallins; D011993:Recombinant Fusion Proteins; D038205:beta-Crystallin A Chain