title: Identifying three-dimensional structures of autophosphorylation complexes in crystals of protein kinases.
abstract: Protein kinase autophosphorylation is a common regulatory mechanism in cell signaling pathways. Crystal structures of several homomeric protein kinase complexes have a serine, threonine, or tyrosine autophosphorylation site of one kinase monomer located in the active site of another monomer, a structural complex that we call an "autophosphorylation complex." We developed and applied a structural bioinformatics method to identify all such autophosphorylation complexes in x-ray crystallographic structures in the Protein Data Bank (PDB). We identified 15 autophosphorylation complexes in the PDB, of which five complexes had not previously been described in the publications describing the crystal structures. These five complexes consist of tyrosine residues in the N-terminal juxtamembrane regions of colony-stimulating factor 1 receptor (CSF1R, Tyr(561)) and ephrin receptor A2 (EPHA2, Tyr(594)), tyrosine residues in the activation loops of the SRC kinase family member LCK (Tyr(394)) and insulin-like growth factor 1 receptor (IGF1R, Tyr(1166)), and a serine in a nuclear localization signal region of CDC-like kinase 2 (CLK2, Ser(142)). Mutations in the complex interface may alter autophosphorylation activity and contribute to disease; therefore, we mutated residues in the autophosphorylation complex interface of LCK and found that two mutations impaired autophosphorylation (T445V and N446A) and mutation of Pro(447) to Ala, Gly, or Leu increased autophosphorylation. The identified autophosphorylation sites are conserved in many kinases, suggesting that, by homology, these complexes may provide insight into autophosphorylation complex interfaces of kinases that are relevant drug targets.
authors.affiliation: Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
authors.forename: Qifang
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
authors.forename: Kimberly L
authors.initials: KL
authors.lastname: Malecka
authors.affiliation: Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: Fink
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: E Joseph
authors.initials: EJ
authors.lastname: Jordan
authors.affiliation: Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Duffy
authors.affiliation: Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Kolander
authors.affiliation: Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Peterson
authors.affiliation: Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA. roland.dunbrack@fccc.edu.
authors.forename: Roland L
authors.initials: RL
authors.lastname: Dunbrack
mesh_terms: D019943:Amino Acid Substitution; D030562:Databases, Protein; D057809:HEK293 Cells; D006801:Humans; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020125:Mutation, Missense; D010766:Phosphorylation / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D036104:Receptor, EphA2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: C066780:Clk dual-specificity kinases; D011505:Protein-Tyrosine Kinases; D036104:Receptor, EphA2; D016186:Receptor, Macrophage Colony-Stimulating Factor; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D017346:Protein Serine-Threonine Kinases