title: Ceramide kinase targeting and activity determined by its N-terminal pleckstrin homology domain.
abstract: The N-terminus of ceramide kinase (CERK) is thought to be myristoylated and to contain a pleckstrin homology (PH) domain. We found that deletion of this region (DeltaPH-CERK) ablates activity. This is not due to prevention of N-terminal myristoylation since a G2A CERK mutant, which cannot be myristoylated, was active. CERK was able to bind liposomes, as well as the isolated unmyristoylated PH domain; DeltaPH-CERK was not. Upon analysis of EGFP-tagged proteins, CERK was found associated with the Golgi complex. Osmotic cell swelling induced translocation of CERK to the plasma membrane and formation of large vesicles displaying bound CERK. None of these features occurred with DeltaPH-CERK, which remained disseminated throughout the cytoplasm. These findings show that the PH domain of CERK is essential for localization, translocation, and activity of this lipid kinase.
authors.affiliation: Novartis Institute for BioMedical Research Vienna, Brunnerstrasse 59, A-1235 Vienna, Austria.
authors.forename: Adeline
authors.initials: A
authors.lastname: Carré
authors.forename: Christine
authors.initials: C
authors.lastname: Graf
authors.forename: Samantha
authors.initials: S
authors.lastname: Stora
authors.forename: Diana
authors.initials: D
authors.lastname: Mechtcheriakova
authors.forename: Robert
authors.initials: R
authors.lastname: Csonga
authors.forename: Nicole
authors.initials: N
authors.lastname: Urtz
authors.forename: Andreas
authors.initials: A
authors.lastname: Billich
authors.forename: Thomas
authors.initials: T
authors.lastname: Baumruker
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bornancin
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000737:chemistry; D006801:Humans; D008081:Liposomes / Q000378:metabolism; D009997:Osmotic Pressure; D010750:Phosphoproteins / Q000737:chemistry; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D021381:Protein Transport
chemical_list: D001798:Blood Proteins; D008081:Liposomes; D010750:Phosphoproteins; C039077:platelet protein P47; D017853:Phosphotransferases (Alcohol Group Acceptor); C066324:ceramide kinase