| Autor: |
Willott, E., Balda, M. S., Heintzelman, M., Jameson, B., Anderson, J. M. |
| Zdroj: |
American Journal of Physiology - Cell Physiology; May 1992, Vol. 262 Issue: 5 pC1119-C1124, 6p |
| Abstrakt: |
ZO-1 is a peripheral membrane protein of approximately 225 kDa located on the cytoplasmic side of all tight junctions. ZO-1 cDNA sequencing disclosed the presence of a 240-bp sequence in only some of the ZO-1 cDNAs studied. This 240-bp region encoded an inframe insertion of 80 amino acids, named motif-alpha. Expression of the predicted transcripts in normal rat and human tissues and in human epithelial cell lines (Caco-2, T84, Hep G2) was shown by reverse transcription of RNA and then DNA amplification. Immunoblot analysis showed both protein isoforms were present; however, in different cell lines, their amounts differed markedly relative to each other. Immunolocalization at light and ultrastructural levels, using antibodies generated against motif-alpha or shared sequences flanking it, indicated both forms localized indistinguishably to tight junctions. These observations demonstrate the existence and variable expression of ZO-1 isoforms and raise the question whether these isoforms contribute to tight junction diversity in different epithelia. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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