Primary structure of the rat kidney band 3 anion exchange protein deduced from a cDNA.
A rat kidney cDNA library was screened using an oligonucleotide hybridization probe derived from an amino acid sequence of the mouse erythrocyte Band 3 Cl-/HCO3- exchanger. Ten cDNAs representing a single class of mRNA and encoding the kidney Band 3 anion exchanger were isolated. Analysis of the deduced amino acid sequence revealed that kidney Band 3 is a truncated version of erythrocyte Band 3. The 848-amino acid rat kidney protein is virtually identical to mouse erythrocyte Band 3 except that it lacks the first 79 amino acids of the N-terminal cytoplasmic domain. Exons 1, 2, and 3 of the Band 3 gene, which are included in erythrocyte Band 3 mRNA, are not present in the kidney cDNA. The 5'-untranslated regions of kidney Band 3 transcripts contain sequences from the third intron and exons 4 and 5 of the Band 3 gene. The sequences from exons 4 and 5 that serve as untranslated sequences in the rat kidney mRNA have the potential to encode amino acids 46-79 of erythrocyte Band 3 but are not part of an open reading frame; the apparent translation initiation site corresponds to codon 80 of mouse erythrocyte Band 3 mRNA. Northern blot hybridization studies indicate that two additional Band 3 mRNAs, which differ in size from the major 4.5-kilobase pair transcript in kidney, are expressed at low levels in kidney and brain.
Kudrycki
K E
KE
Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Ohio 45267-0524.
Shull
G E
GE
D000595:Amino Acid Sequence; D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000235:genetics*; D001483:Base Sequence; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification; D004912:Erythrocytes / Q000032:analysis; D005091:Exons; D006801:Humans; D007438:Introns; D007668:Kidney / Q000032:analysis*; D051379:Mice; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D001457:Anion Exchange Protein 1, Erythrocyte; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D004247:DNA