title: Characterization and expression of AmphiCL encoding cathepsin l proteinase from amphioxus Branchiostoma belcheri tsingtauense.
abstract: An amphioxus complementary DNA, AmphiCL, encoding cathepsin L proteinase was isolated from the gut cDNA library of Branchiostoma belcheri tsingtauense. It is 1480 bp long, and its longest open reading frame codes for a precursor protein, which consists of 327 amino acid residues including a signal peptide (preregion), a propeptide, and a mature proteinase. Northern blot showed that AmphiCL was expressed in the gill, testis, hepatic cecum, and hind-gut with a molecular size of about 1480 bp. AmphiCL was also expressed at low level in the muscle, notochord, and ovary as revealed by the more sensitive reverse transcriptase polymerase chain reaction techniques. Semiquantitative RT-PCR also showed that although AmphiCL expression in the gut was significantly downregulated by feeding Arthrospira platensis powder, a protein-rich food, its expression in the same tissue was upregulated by exposure to lipopolysaccharide, an integral component of the outer membrane of gram-negative bacteria. This suggests that although the involvement of AmphiCL in food digestion remains to be confirmed, AmphiCL may play a role in inflammatory reaction in amphioxus.
authors.affiliation: Department of Marine Biology, Ocean University of China, 5 Yushan Road, 266003 Qingdao, PR, China.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Wang
authors.forename: Shicui
authors.initials: S
authors.lastname: Zhang
authors.forename: Zhenhui
authors.initials: Z
authors.lastname: Liu
authors.forename: Hongyan
authors.initials: H
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D056668:Cathepsin L; D002403:Cathepsins / Q000235:genetics* / Q000378:metabolism*; D002816:Chordata, Nonvertebrate / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D016000:Cluster Analysis; D003546:Cysteine Endopeptidases / Q000235:genetics* / Q000378:metabolism*; D004064:Digestive System / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D015723:Gene Library; D005880:Gills / Q000378:metabolism; D006066:Gonads / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity; D008969:Molecular Sequence Data; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D008070:Lipopolysaccharides; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D056668:Cathepsin L