title: Transcriptional analysis of three major putative phosphatidylinositol kinase genes in a parasitic protozoan, Giardia lamblia.
abstract: The current investigation evaluates the expression of phosphatidylinositol kinase (PIK) genes in the parasitic protozoan, Giardia lamblia. The G. lamblia Genome Database revealed the presence of two putative phosphatidylinositol-3-kinase (gPI3K) and one phosphatidylinositol-4-kinase (gPI4K) genes resembling the catalytic subunit of eukaryotic PIKs. Primers, designed to amplify mRNA of these three genes, were used to measure transcription by quantitative reverse-transcriptase polymerase chain reactions. Results suggest that all three PIK genes are expressed in non-encysting and encysting trophozoites. The relative levels of the mRNA were highest in parasites cultured in pre-encysting medium that contained no bile. Two inhibitors of PI3K, LY 294002 and wortmannin were found to inhibit the growth of the trophozoite in culture. However, wortmannin was more effective than LY294002. Altogether, the present study indicates that Giardia is capable of expressing PIKs that are necessary for the growth and differentiation of this pathogen.
authors.affiliation: Infectious Diseases and Immunology Unit, The Border Biomedical Research Center (BBRC), and Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas 79968-0519, USA.
authors.forename: Yunuen
authors.initials: Y
authors.lastname: Hernandez
authors.forename: Gus
authors.initials: G
authors.lastname: Zamora
authors.forename: Suparna
authors.initials: S
authors.lastname: Ray
authors.forename: Jaime
authors.initials: J
authors.lastname: Chapoy
authors.forename: Edna
authors.initials: E
authors.lastname: Chavez
authors.forename: Robert
authors.initials: R
authors.lastname: Valvarde
authors.forename: Ebonye
authors.initials: E
authors.lastname: Williams
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Aley
authors.forename: Siddhartha
authors.initials: S
authors.lastname: Das
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase / Q000235:genetics* / Q000378:metabolism; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D002867:Chromones / Q000494:pharmacology; D017125:Genes, Protozoan; D016829:Giardia lamblia / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D009025:Morpholines / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics* / Q000378:metabolism; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D053058:Trophozoites / Q000187:drug effects / Q000201:enzymology; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D002867:Chromones; D009025:Morpholines; D010726:Phosphodiesterase Inhibitors; D012333:RNA, Messenger; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D019869:Phosphatidylinositol 3-Kinases; D019870:1-Phosphatidylinositol 4-Kinase; D000077191:Wortmannin