Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/27733
- The LFA-1-associated molecule PTA-1 (CD226) on T cells forms a dynamic molecular complex with protein 4.1G and human discs large
Ralston, Kylie J.;
Hird, Samantha L.;
Scott, Judith L.;
Thorne, Rick F.;
Berndt, Michael C.;
Boyd, Andrew W.;
Burns, Gordon F.
- Clustering of the T cell integrin, LFA-1, at specialized regions of intercellular contact initiates integrin-mediated adhesion and downstream signaling, events that are necessary for a successful immunological response. But how clustering is achieved and sustained is not known. Here we establish that an LFA-1-associated molecule, PTA-1, is localized to membrane rafts and binds the carboxyl-terminal domain of isoforms of the actin-binding protein 4.1G. Protein 4.1 is known to associate with the membrane-associated guanylate kinase homologue, human discs large. We show that the carboxyl-terminal peptide of PTA-1 also can bind human discs large and that the presence or absence of this peptide greatly influences binding between PTA-1 and different isoforms of 4.1G. T cell stimulation with phorbol ester or PTA-1 cross-linking induces PTA-1 and 4.1G to associate tightly with the cytoskeleton, and the PTA-1 from such activated cells now can bind to the amino-terminal region of 4.1G. We propose that these dynamic associations provide the structural basis for a regulated molecular adhesive complex that serves to cluster and transport LFA-1 and associated molecules.
- Journal of Biological Chemistry Vol. 279, Issue 32, p. 33816-33828
- Publisher Link
- American Society for Biochemistry and Molecular Biology
- Resource Type
- journal article