Details

Autor(en) / Beteiligte

• Ralston, Kylie J.
• Hird, Samantha L.
• Zhang, Xinhai
• Scott, Judith L.
• Jin, Boquan
• Thorne, Rick F.
• Berndt, Michael C.
• Boyd, Andrew W.
• Burns, Gordon F.

Titel

The LFA-1-associated Molecule PTA-1 (CD226) on T Cells Forms a Dynamic Molecular Complex with Protein 4.1G and Human Discs Large

Ist Teil von

• The Journal of biological chemistry, 2004-08, Vol.279 (32), p.33816-33828

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2004

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• 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.