Variant AE2 anion exchanger transcripts accumulate in multiple cell types in the chicken gastric epithelium.
Molecular analyses have resulted in the isolation of two chicken stomach AE2 anion exchanger cDNAs, AE2-1 and AE2-2. The approximately 4.3-kilobase (kb) AE2-1 cDNA contains an open reading frame that encodes a predicted polypeptide of approximately 135 kDa that is homologous to AE2 anion exchangers from other species. The partial approximately 1.7-kb AE2-2 cDNA, which differs from the AE2-1 cDNA in two regions, would be predicted to encode an AE2 polypeptide with an alternative N-terminal cytoplasmic tail. Examination of the distribution of these variant transcripts has revealed that AE2 transcripts ranging in size from approximately 4.4 to approximately 7.3 kb accumulate in various adult tissues. However, in the stomach, the unique sequence at the 5'-end of AE2-1 is preferentially associated with transcripts that range in size from approximately 4.5 to approximately 4.9 kb, while the unique sequence at the 5'-end of AE2-2 is preferentially associated with the approximately 7.3-kb AE2 RNA species. In situ hybridization analyses have further revealed that AE2 transcripts accumulate to very high levels within the acid-secreting epithelial cells of the profound gland in the stomach and, to a lesser extent, within the mucus-secreting cells of the superficial gland that line the stomach lumen. This result suggests that AE2 anion exchangers are involved in the regulation of intracellular pH in each of these gastric epithelial cell types.
Cox
K H
KH
Department of Microbiology and Immunology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
Adair-Kirk
T L
TL
Cox
J V
JV
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D027321:Anion Transport Proteins; D000838:Anions; D017920:Antiporters; D001483:Base Sequence; D002645:Chickens; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005753:Gastric Mucosa / Q000378:metabolism*; D015870:Gene Expression; D017403:In Situ Hybridization; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D064606:SLC4A Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014018:Tissue Distribution
D027321:Anion Transport Proteins; D000838:Anions; D017920:Antiporters; D018076:DNA, Complementary; D008565:Membrane Proteins; D012333:RNA, Messenger; D064606:SLC4A Proteins