Cell-specific expression of the human Na+,K(+)-ATPase beta 2 subunit isoform in the nonpigmented ciliary epithelium.
Invest Ophthalmol Vis Sci
; 36(13): 2717-28, 1995 Dec.
Article
em En
| MEDLINE
| ID: mdl-7499094
ABSTRACT
PURPOSE:
To evaluate the patterns of expression of beta subunit isoforms of the Na+,K(+)-ATPase and H+,K(+)-ATPase in the human eye and to determine the cell-specific distribution of the beta 2 subunit in the human ciliary epithelium.METHODS:
Total RNA extracted from human ocular tissues was screened by Northern blot analysis with cDNA probes for the human Na+,K(+)-ATPase subunit isoforms (beta 1 and beta 2) or the H+,K(+)-ATPase (alpha and beta) subunits. Antibodies were raised to the amino and carboxyl terminal regions of the human beta 2 isoform. Polymerase chain reaction was used to verify the expression of beta 2 subunit in nonpigmented ciliary epithelial cells (NPE).RESULTS:
Transcripts for the Na+,K(+)-ATPase beta 1 and beta 2 subunit isoforms were present at different levels in all the ocular tissues except the lens, which expressed only beta 1. No transcripts for the alpha or beta subunits of the H+,K(+)-ATPase were detected in the eye. Isoform beta 2 specific anti-peptide antibodies V15E (N-terminus) and A18R (C-terminus) recognized a 55- to 60-kDa protein in the ciliary epithelium and the core protein of 32 kDa after N-glycanase treatment. Immunocytochemical localization within the ciliary epithelium indicates that the Na+,K(+)-ATPase beta 2 isoform is expressed preferentially in the NPE cells. The expression of Na+,K(+)-ATPase beta 2 isoform in the human NPE cell line, ODM-2, was confirmed by polymerase chain reaction amplification and Southern blot analysis.CONCLUSIONS:
The Na+,K(+)-ATPase beta 2 subunit isoform, but not H+,K(+)-ATPase, was expressed widely in ocular tissues of the human eye. The restricted cellular distribution of beta 2 isoform within the NPE cells represents an important differential gene marker associated with the multiple alpha subunit isoforms of Na+,K(+)-ATPase.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Corpo Ciliar
/
ATPase Trocadora de Sódio-Potássio
/
Isoenzimas
Limite:
Aged
/
Aged80
/
Humans
/
Infant
/
Middle aged
Idioma:
En
Revista:
Invest Ophthalmol Vis Sci
Ano de publicação:
1995
Tipo de documento:
Article