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A cytoplasmic protein, bystin, interacts with trophinin, tastin, and cytokeratin and may be involved in trophinin-mediated cell adhesion between trophoblast and endometrial epithelial cells

Authors :
Nao Suzuki
Kellie L. Watson
Edgar Ong
Nouna Bakhiet
Takaaki Sato
Robert G. Oshima
Michiko N. Fukuda
Jane Zara
Source :
Proceedings of the National Academy of Sciences. 95:5027-5032
Publication Year :
1998
Publisher :
Proceedings of the National Academy of Sciences, 1998.

Abstract

Trophinin and tastin form a cell adhesion molecule complex that potentially mediates an initial attachment of the blastocyst to uterine epithelial cells at the time of implantation. Trophinin and tastin, however, do not directly bind to each other, suggesting the presence of an intermediary protein. The present study identifies a cytoplasmic protein, named bystin, that directly binds trophinin and tastin. Bystin consists of 306 amino acid residues and is predicted to contain tyrosine, serine, and threonine residues in contexts conforming to motifs for phosphorylation by protein kinases. Database searches revealed a 53% identity of the predicted peptide sequence with the Drosophila bys ( mrr ) gene. Direct protein–protein interactions of trophinin, tastin, and bystin analyzed by yeast two-hybrid assays and by in vitro protein binding assays indicated that binding between bystin and trophinin and between bystin and tastin is enhanced when cytokeratin 8 and 18 are present as the third molecule. Immunocytochemistry of bystin showed that bystin colocalizes with trophinin, tastin, and cytokeratins in a human trophoblastic teratocarcinoma cell, HT-H. It is therefore possible that these molecules form a complex and thus are involved in the process of embryo implantation.

Details

ISSN :
10916490 and 00278424
Volume :
95
Database :
OpenAIRE
Journal :
Proceedings of the National Academy of Sciences
Accession number :
edsair.doi.dedup.....102826520fcc27b7f24689eadd6afa60
Full Text :
https://doi.org/10.1073/pnas.95.9.5027