Beta2 integrin phosphorylation on Thr758 acts as a molecular switch to regulate 14-3-3 and filamin binding. Export

@article{citeulike:2906664, abstract = {Leukocyte integrins of the beta2 family are essential for immune cell-cell adhesion. In activated cells, beta2 integrins are phosphorylated on the cytoplasmic Thr758, leading to 14-3-3 protein recruitment to the beta2 integrin. The mutation of this phosphorylation site impairs cell adhesion, actin reorganization, and cell spreading. Thr758 is contained in a Thr triplet of beta2 that also mediates binding to filamin. Here, we investigated the binding of filamin, talin, and 14-3-3 proteins to phosphorylated and unphosphorylated beta2 integrins by biochemical methods and x-ray crystallography. 14-3-3 proteins bound only to the phosphorylated integrin cytoplasmic peptide, with a high affinity (K(d), 261 nM), whereas filamin bound only the unphosphorylated integrin cytoplasmic peptide (K(d), 0.5 mM). Phosphorylation did not regulate talin binding to beta2 directly, but 14-3-3 was able to outcompete talin for the binding to phosphorylated beta2 integrin. X-ray crystallographic data clearly explained how phosphorylation eliminated filamin binding and induced 14-3-3 protein binding. Filamin knockdown in T cells led to an increase in stimulated cell adhesion to ICAM-1-coated surfaces. Our results suggest that the phosphorylation of beta2 integrins on Thr758 acts as a molecular switch to inhibit filamin binding and allow 14-3-3 protein binding to the integrin cytoplasmic domain, thereby modulating T-cell adhesion.}, address = {Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, Jyvaskyla, Finland.}, author = {Takala, Heikki and Nurminen, Elisa and Nurmi, Susanna M. and Aatonen, Maria and Strandin, Tomas and Takatalo, Maarit and Kiema, Tiila and Gahmberg, Carl G. and Yl\"{a}nne, Jari and Fagerholm, Susanna C.}, citeulike-article-id = {2906664}, citeulike-linkout-0 = {http://dx.doi.org/10.1182/blood-2007-12-127795}, citeulike-linkout-1 = {http://bloodjournal.hematologylibrary.org/cgi/content/abstract/112/5/1853}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/18550856}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=18550856}, day = {1}, doi = {10.1182/blood-2007-12-127795}, issn = {1528-0020}, journal = {Blood}, keywords = {filamin, lfa-1}, month = {September}, number = {5}, pages = {1853--1862}, posted-at = {2008-08-25 22:01:51}, priority = {2}, title = {Beta2 integrin phosphorylation on Thr758 acts as a molecular switch to regulate 14-3-3 and filamin binding.}, url = {http://dx.doi.org/10.1182/blood-2007-12-127795}, volume = {112}, year = {2008} }

TY - JOUR ID - citeulike:2906664 L3 - citeulike-article-id:2906664 N2 - Leukocyte integrins of the beta2 family are essential for immune cell-cell adhesion. In activated cells, beta2 integrins are phosphorylated on the cytoplasmic Thr758, leading to 14-3-3 protein recruitment to the beta2 integrin. The mutation of this phosphorylation site impairs cell adhesion, actin reorganization, and cell spreading. Thr758 is contained in a Thr triplet of beta2 that also mediates binding to filamin. Here, we investigated the binding of filamin, talin, and 14-3-3 proteins to phosphorylated and unphosphorylated beta2 integrins by biochemical methods and x-ray crystallography. 14-3-3 proteins bound only to the phosphorylated integrin cytoplasmic peptide, with a high affinity (K(d), 261 nM), whereas filamin bound only the unphosphorylated integrin cytoplasmic peptide (K(d), 0.5 mM). Phosphorylation did not regulate talin binding to beta2 directly, but 14-3-3 was able to outcompete talin for the binding to phosphorylated beta2 integrin. X-ray crystallographic data clearly explained how phosphorylation eliminated filamin binding and induced 14-3-3 protein binding. Filamin knockdown in T cells led to an increase in stimulated cell adhesion to ICAM-1-coated surfaces. Our results suggest that the phosphorylation of beta2 integrins on Thr758 acts as a molecular switch to inhibit filamin binding and allow 14-3-3 protein binding to the integrin cytoplasmic domain, thereby modulating T-cell adhesion. IS - 5 JF - Blood SN - 1528-0020 AD - Department of Biological and Environmental Science and Nanoscience Center, University of Jyvaskyla, Jyvaskyla, Finland. EP - 1862 TI - Beta2 integrin phosphorylation on Thr758 acts as a molecular switch to regulate 14-3-3 and filamin binding. VL - 112 SP - 1853 KW - filamin KW - lfa-1 AU - Takala, Heikki AU - Nurminen, Elisa AU - Nurmi, Susanna AU - Aatonen, Maria AU - Strandin, Tomas AU - Takatalo, Maarit AU - Kiema, Tiila AU - Gahmberg, Carl AU - Ylänne, Jari AU - Fagerholm, Susanna PY - 2008/09/01/ UR - http://dx.doi.org/10.1182/blood-2007-12-127795 ER -