title: Identification and characterization of CKLiK, a novel granulocyte Ca(++)/calmodulin-dependent kinase.
abstract: Human granulocytes are characterized by a variety of specific effector functions involved in host defense. Several widely expressed protein kinases have been implicated in the regulation of these effector functions. A polymerase chain reaction-based strategy was used to identify novel granulocyte-specific kinases. A novel protein kinase complementary DNA with an open reading frame of 357 amino acids was identified with homology to calcium-calmodulin-dependent kinase I (CaMKI). This has been termed CaMKI-like kinase (CKLiK). Analysis of CKLiK messenger RNA (mRNA) expression in hematopoietic cells demonstrated an almost exclusive expression in human polymorphonuclear leukocytes (PMN). Up-regulation of CKLiK mRNA occurs during neutrophilic differentiation of CD34(+) stem cells. CKLiK kinase activity was dependent on Ca(++) and calmodulin as analyzed by in vitro phosphorylation of cyclic adenosine monophosphate responsive element modulator (CREM). Furthermore, CKLiK- transfected cells treated with ionomycin demonstrated an induction of CRE- binding protein (CREB) transcriptional activity compared to control cells. Additionally, CaMK-kinasealpha enhanced CKLiK activity. In vivo activation of CKLiK was shown by addition of interleukin (IL)-8 to a myeloid cell line stably expressing CKLiK. Furthermore inducible activation of CKLiK was sufficient to induce extracellular signal-related kinase (ERK) mitogen-activated protein (MAP) kinase activity. These data identify a novel Ca(++)/calmodulin-dependent PMN- specific kinase that may play a role in Ca(++)-mediated regulation of human granulocyte functions.
authors.affiliation: Department of Pulmonary Diseases, University Medical Centre Utrecht, 3584 CX Utrecht, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Verploegen
authors.forename: J W
authors.initials: JW
authors.lastname: Lammers
authors.forename: L
authors.initials: L
authors.lastname: Koenderman
authors.forename: P J
authors.initials: PJ
authors.lastname: Coffer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000097:blood* / Q000737:chemistry / Q000235:genetics; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D006098:Granulocytes / Q000201:enzymology*; D006412:Hematopoietic Stem Cells / Q000201:enzymology; D006801:Humans; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014162:Transfection
chemical_list: D011993:Recombinant Fusion Proteins; D015500:Chloramphenicol O-Acetyltransferase; C517596:CAMK1 protein, human; C517601:CAMK1D protein, human; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D017871:Calcium-Calmodulin-Dependent Protein Kinases