Asymmetric PI3K Activity in Lymphocytes Organized by a PI3K-Mediated Polarity Pathway
Yen-Hua Chen,
Radomir Kratchmarov,
Wen-Hsuan W. Lin,
Nyanza J. Rothman,
Bonnie Yen,
William C. Adams,
Simone A. Nish,
Jeffrey C. Rathmell,
Steven L. Reiner
Affiliations
Yen-Hua Chen
Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
Radomir Kratchmarov
Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
Wen-Hsuan W. Lin
Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
Nyanza J. Rothman
Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
Bonnie Yen
Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
William C. Adams
Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
Simone A. Nish
Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
Jeffrey C. Rathmell
Vanderbilt Center for Immunobiology, Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
Steven L. Reiner
Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
Unequal transmission of nutritive signaling during cell division establishes fate disparity between sibling lymphocytes, but how asymmetric signaling becomes organized is not understood. We show that receptor-associated class I phosphatidylinositol 3-kinase (PI3K) signaling activity, indexed by phosphatidylinositol (3,4,5)-trisphosphate (PIP3) staining, is spatially restricted to the microtubule-organizing center and subsequently to one pole of the mitotic spindle in activated T and B lymphocytes. Asymmetric PI3K activity co-localizes with polarization of antigen receptor components implicated in class I PI3K signaling and with facultative glucose transporters whose trafficking is PI3K dependent and whose abundance marks cells destined for differentiation. Perturbation of class I PI3K activity disrupts asymmetry of upstream antigen receptors and downstream glucose transporter traffic. The roles of PI3K signaling in nutrient utilization, proliferation, and gene expression may have converged with the conserved role of PI3K signaling in cellular symmetry breaking to form a logic for regenerative lymphocyte divisions.
