A novel integrin (alpha E beta 4) from human epithelial cells suggests a fourth family of integrin adhesion receptors.
A new member of the integrin superfamily of adhesion receptors was isolated from human epithelial cells. Analogously to other integrins, this molecule is a heterodimer comprised of structurally unrelated subunits, both glycosylated. Unequivocal amino-acid sequence homologies were observed between these subunits and integrin alpha and beta chain sequences, indicating that this epithelial heterodimer is a novel integrin. No obvious serologic cross-reactivities were detected with other integrins. The beta chain of the epithelial integrin displayed a mol. wt significantly higher than other integrin beta chains, possibly due to a large sialic acid content. Integrin heterodimers are grouped into three families, based on which of three beta chains (beta 1, beta 2 and beta 3) they contain. Therefore, the epithelial integrin may represent the prototype of a fourth integrin family, because it contains a structurally distinct beta chain. The designation alpha E beta 4 is proposed for this novel human integrin.
Kajiji
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Department of Immunology, Research Institute of Scripps Clinic, La Jolla, CA 92037.
Tamura
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RN
Quaranta
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D000595:Amino Acid Sequence; D002448:Cell Adhesion; D004848:Epithelium / Q000032:analysis / Q000276:immunology; D006801:Humans; D007120:Immunochemistry; D039663:Integrin beta4; D016023:Integrins; D008562:Membrane Glycoproteins / Q000145:classification / Q000276:immunology / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011487:Protein Conformation; D011956:Receptors, Cell Surface / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism
C059834:ITGB4 protein, human; D039663:Integrin beta4; D016023:Integrins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface