title: An active kinase domain is required for retention of PKCθ at the T cell immunological synapse.
abstract: Protein kinase Cθ (PKCθ) is a serine/threonine kinase that plays an essential role in antigen-regulated responses of T lymphocytes. Upon antigen stimulation, PKCθ is rapidly recruited to the immunological synapse (IS), the region of contact between the T cell and antigen-presenting cell. This behavior is unique among T cell PKC isoforms. To define domains of PKCθ required for retention at the IS, we generated deletion and point mutants of PKCθ. We used quantitative imaging analysis to assess IS retention of PKCθ mutants in antigen-stimulated T cell clones. Deletion of the kinase domain or site-directed mutation of a subset of known PKCθ phosphorylation sites abrogated or significantly reduced IS retention, respectively. IS retention did not correlate with phosphorylation of specific PKCθ residues but rather with kinase function. Thus PKCθ catalytic competence is essential for stable IS retention.
authors.affiliation: Department of Microbiology and Immunology and Center for Neuroscience and Regenerative Medicine, Uniformed Services University, Bethesda, MD 20814, USA.
authors.forename: Natalia G
authors.initials: NG
authors.lastname: Cartwright
authors.forename: Anuj K
authors.initials: AK
authors.lastname: Kashyap
authors.forename: Brian C
authors.initials: BC
authors.lastname: Schaefer
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D020134:Catalytic Domain; D002478:Cells, Cultured; D049452:Green Fluorescent Proteins / Q000378:metabolism; D054992:Immunological Synapses / Q000378:metabolism*; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D011493:Protein Kinase C / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000074121:Protein Kinase C-theta; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D059010:Single-Cell Analysis
chemical_list: D007527:Isoenzymes; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C489593:Prkcq protein, mouse; D011493:Protein Kinase C; D000074121:Protein Kinase C-theta