title: Cloning, functional expression and expression studies of the nitrate transporter gene from Chlorella sorokiniana (strain 211-8k).
abstract: The nitrate transporter from Chlorella sorokiniana (accession number AY026523) has been cloned by screening a cDNA library based on mRNA isolated after 30 min treatment of Chlorella with 5 mM nitrate and with a RT-PCR product (730 bp) as a probe. The Chlorella sequence has similarity to known nitrate transporters of the NRT2 family (high-affinity nitrate transporters). The cDNA clone was used for functional expression in Xenopus oocytes and a nitrate-dependent current was measured at pH 5.5 but not at pH 7.4. A second algal gene or a second gene product was not needed for functional expression in Xenopus. Inhibitor studies in Chlorella indicated that protein phosphorylation/dephosphorylation is involved in nitrate induction of ChNRT2.1. In addition to nitrate, ChNRT2.1 expression is induced by nitroprusside, a NO donor, and is affected by glucose.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D027321:Anion Transport Proteins / Q000235:genetics* / Q000378:metabolism; D002708:Chlorella / Q000187:drug effects / Q000235:genetics*; D003001:Cloning, Molecular; D003513:Cycloheximide / Q000494:pharmacology; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D008969:Molecular Sequence Data; D000091285:Nitrate Transporters; D009566:Nitrates / Q000494:pharmacology; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects / Q000502:physiology; D010766:Phosphorylation / Q000187:drug effects; D010802:Phylogeny; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014981:Xenopus
chemical_list: D027321:Anion Transport Proteins; D018076:DNA, Complementary; D000091285:Nitrate Transporters; D009566:Nitrates; D020030:Nitric Oxide Donors; D011500:Protein Synthesis Inhibitors; D000644:Quaternary Ammonium Compounds; D012333:RNA, Messenger; D009599:Nitroprusside; D003513:Cycloheximide