Integrin heterodimer and receptor complexity in avian and mammalian cells.
We report data showing that the integrin receptor complex in chickens contains several discrete heterodimers all sharing the beta 1-integrin subunit combined separately with different alpha-subunits. Using antisera to synthetic peptides based on cDNA sequences of chicken and human alpha-integrin subunits to analyze the integrin complement of avian and mammalian cells, we show that band 2 of the chicken integrin complex contains alpha-subunits related to both alpha 3- and alpha 5-subunits of human integrins. alpha 3 beta 1 and alpha 5 beta 1 have both previously been shown in human cells to be fibronectin receptors and alpha 3 beta 1 can also act as a receptor for laminin and collagen. We also provide evidence for the presence, in band 1 of the chicken integrin complex, of a third integrin alpha-subunit which is also alpha 5 related. This integrin subunit exists in a separate heterodimer complex with beta 1 and binds to fibronectin-affinity columns. These results provide explanations for published data showing that the avian integrin complex contains receptor activity for a variety of extracellular matrix proteins. We conclude that the chicken integrin complex comprises a set of beta 1-integrin heterodimers equivalent to the human VLA antigens and includes at least two fibronectin receptors. Finally, we show that chicken embryo fibroblasts also contain a beta 3-class integrin related to the RGD receptors defined in various human cells.
Hynes
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RO
Center for Cancer Research, Massachusetts Institute of Technology, Cambridge 02139.
Marcantonio
E E
EE
Stepp
M A
MA
Urry
L A
LA
Yee
G H
GH
D000818:Animals; D015153:Blotting, Western; D002448:Cell Adhesion; D002645:Chickens; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D007158:Immunologic Techniques; D016023:Integrins; D008024:Ligands; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins / Q000502:physiology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D005810:Multigene Family
D005353:Fibronectins; D016023:Integrins; D008024:Ligands; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D004247:DNA