title: Molecular cloning and characterization of an ATP-binding cassette (ABC) transmembrane transporter from the white shrimp Litopenaeusvannamei.
abstract: ATP-binding cassette transmembrane transporters (ABC transporters) have a potential role in drug and xenobiotic resistance. Here, we report for the first time the cloning of an ABC transporter from white shrimp Litopenaeusvannamei (designated LvABCG), along with a study of its phylogenetic relationships, and measurements of its expression in different shrimp tissues exposed to cadmium and pH stress (acidic and alkaline conditions). Sequence analysis showed that LvABCG shares many similarities with the white/ABC transmembrane transporter, including two conserved regions: a highly conserved ATP-binding cassette (ABC) and transmembrane domain (TMD). Spatial analyses of transcript levels for ABCG in shrimp tissues, using reverse transcript PCR, revealed the highest transcript level in the hepatopancreas, less in the intestine and stomach, and none in the other tissues examined. The ABC transporter mRNA transcript in the hepatopancreas of L.vannamei was significantly up-regulated after 1.5 h and 24 h of exposure to alkaline and acidic conditions, respectively. LvABCG was also induced in intestine, but was downregulated in the stomach under the alkaline treatment. Upon exposure to cadmium (4.25 micromol L(-1) and 8.5 micromol L(-1)) for 48 h, the mRNA expression of LvABCG was up-regulated 4.79-fold (at 6 h) and 2.09-fold (at 12 h) in the hepatopancreas. LvABCG was also induced in the stomach after exposure to 4.25 micromol L(-1) cadmium, but downregulated in the stomach and intestine after exposure to 8.5 micromol L(-1) cadmium. These findings indicate that LvABCG might play an important role in the physiological changes related to metabolism and cell detoxification that occur when Pacific white shrimp are exposed to cadmium and pH stress.
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors: Jun
authors: J
authors: Zhou
authors: Wen-Yin
authors: WY
authors: He
authors: Wei-Na
authors: WN
authors: Wang
authors: Cheng-Wei
authors: CW
authors: Yang
authors: Lei
authors: L
authors: Wang
authors: Yu
authors: Y
authors: Xin
authors: Juan
authors: J
authors: Wu
authors: Dan-xia
authors: DX
authors: Cai
authors: Yuan
authors: Y
authors: Liu
authors: An-Li
authors: AL
authors: Wang
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002104:Cadmium / Q000633:toxicity; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D005753:Gastric Mucosa / Q000378:metabolism; D005786:Gene Expression Regulation; D043143:Hepatopancreas / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000378:metabolism; D008969:Molecular Sequence Data; D033561:Penaeidae / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological; D013997:Time Factors; D014018:Tissue Distribution; D023382:Toxicity Tests, Acute
chemical_list: D018528:ATP-Binding Cassette Transporters; D018076:DNA, Complementary; D012333:RNA, Messenger; D002104:Cadmium