Apical polarity of Na,K-ATPase in retinal pigment epithelium is linked to a reversal of the ankyrin-fodrin submembrane cytoskeleton - PubMed (original) (raw)

Apical polarity of Na,K-ATPase in retinal pigment epithelium is linked to a reversal of the ankyrin-fodrin submembrane cytoskeleton

D Gundersen et al. J Cell Biol. 1991 Mar.

Abstract

In striking contrast to most other transporting epithelia (e.g., urinary or digestive systems), where Na,K-ATPase is expressed basolaterally, the retinal pigment epithelium (RPE) cells display Na,K-ATPase pumps on the apical membrane. We report here studies aimed to identify the mechanisms underlying this polarity "reversal" of the RPE Na,K-ATPase. By immunofluorescence on thin frozen sections, both alpha and beta subunits were localized on the apical surface of both freshly isolated rat RPE monolayers and RPE monolayers grown in culture. The polarity of the RPE cell is not completely reversed, however, since aminopeptidase, an apically located protein in kidney epithelia, was also found on the apical surface of RPE cells. We used subunit- and isoform-specific cDNA probes to determine that RPE Na,K-ATPase has the same isoform (alpha 1) as the one found in kidney. Ankyrin and fodrin, proteins of the basolateral membrane cytoskeleton of kidney epithelial cells known to be associated with the Na,K-ATPase (Nelson, W. J., and R. W. Hammerton. 1989. J. Cell Biol. 110:349-357) also displayed a reversed apical localization in RPE and were intimately associated to Na,K-ATPase, as revealed by cross-linking experiments. These results indicate that an entire membrane-cytoskeleton complex is assembled with opposite polarity in RPE cells. We discuss our observations in the context of current knowledge on protein sorting mechanisms in epithelial cells.

PubMed Disclaimer

Cited by

The inner mantle of the giant clam, Tridacna squamosa, expresses a basolateral Na+/K+-ATPase α-subunit, which displays light-dependent gene and protein expression along the shell-facing epithelium.
Boo MV, Hiong KC, Choo CYL, Cao-Pham AH, Wong WP, Chew SF, Ip YK. Boo MV, et al. PLoS One. 2017 Oct 19;12(10):e0186865. doi: 10.1371/journal.pone.0186865. eCollection 2017. PLoS One. 2017. PMID: 29049367 Free PMC article.
Profound re-organization of cell surface proteome in equine retinal pigment epithelial cells in response to in vitro culturing.
Szober CM, Hauck SM, Euler KN, Fröhlich KJ, Alge-Priglinger C, Ueffing M, Deeg CA. Szober CM, et al. Int J Mol Sci. 2012 Oct 31;13(11):14053-72. doi: 10.3390/ijms131114053. Int J Mol Sci. 2012. PMID: 23203049 Free PMC article.
Sodium pump localization in epithelia.
Bystriansky JS, Kaplan JH. Bystriansky JS, et al. J Bioenerg Biomembr. 2007 Dec;39(5-6):373-8. doi: 10.1007/s10863-007-9100-3. J Bioenerg Biomembr. 2007. PMID: 17972022 Review.
Chloride intracellular channel 4 is critical for the epithelial morphogenesis of RPE cells and retinal attachment.
Chuang JZ, Chou SY, Sung CH. Chuang JZ, et al. Mol Biol Cell. 2010 Sep 1;21(17):3017-28. doi: 10.1091/mbc.E09-10-0907. Epub 2010 Jul 7. Mol Biol Cell. 2010. PMID: 20610659 Free PMC article.
Distinguishing roles of the membrane-cytoskeleton and cadherin mediated cell-cell adhesion in generating different Na+,K(+)-ATPase distributions in polarized epithelia.
Marrs JA, Napolitano EW, Murphy-Erdosh C, Mays RW, Reichardt LF, Nelson WJ. Marrs JA, et al. J Cell Biol. 1993 Oct;123(1):149-64. doi: 10.1083/jcb.123.1.149. J Cell Biol. 1993. PMID: 8408194 Free PMC article.

References

1. Nature. 1960 Oct 8;188:114-8 - PubMed
1. J Biol Chem. 1990 Feb 25;265(6):3528-34 - PubMed
1. Proc Natl Acad Sci U S A. 1987 Dec;84(24):9030-4 - PubMed
1. Genomics. 1988 Feb;2(2):128-38 - PubMed
1. J Biol Chem. 1988 Mar 25;263(9):4347-54 - PubMed

Apical polarity of Na,K-ATPase in retinal pigment epithelium is linked to a reversal of the ankyrin-fodrin submembrane cytoskeleton - PubMed (original) (raw)