title: Grass carp (Ctenopharyngodon idellus) invariant chain of the MHC class II chaperone protein associates with the class I molecule.
abstract: The invariant chain (Ii) is an important immune molecule, as it assists major histocompatibility complex (MHC) class II molecules to present antigenic peptides. The relationship between the Ii and MHC molecules in teleosts remains poorly understood. This study focused on the molecular structure of grass carp Ii (gIi), its organ distribution, correlations with gene transcription, and the association with MHC. gIi cDNA was cloned using designed degenerate primers and the rapid amplification of cDNA ends method (RACE). The gIi sequence was 92%-96% similar to that of other teleosts, but only 52%-67% similar to that of mammals, respectively. The gIi gene was distributed in all 12 organs examined by PCR. The gIi gene transcription levels were markedly higher in organs enriched with immune cells than in other organs (P < 0.01). Moreover, positive correlations were detected between transcription levels of the gIi and gMhcI or II genes in different organs (r = 8.415-8.523, P = 0.001). The gIi co-localized on endomembrane systems with either class I or II molecules in co-transfected cells observed by a laser confocal. Further testing confirmed that the gIi bound gMHCI and II molecules. Taken together, these results indicate that the gIi is associated with MHC class I and II molecules, suggesting homology of both MHC molecules.
authors.affiliation: Key Laboratory of Zoonoses of Anhui Province, Anhui Agricultural University, Hefei, Anhui, 230036, China.
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Chen
authors.affiliation: Key Laboratory of Zoonoses of Anhui Province, Anhui Agricultural University, Hefei, Anhui, 230036, China.
authors.forename: Hai-Bin
authors.initials: HB
authors.lastname: Lin
authors.affiliation: Key Laboratory of Zoonoses of Anhui Province, Anhui Agricultural University, Hefei, Anhui, 230036, China.
authors.forename: Jin-Chun
authors.initials: JC
authors.lastname: Li
authors.affiliation: Key Laboratory of Zoonoses of Anhui Province, Anhui Agricultural University, Hefei, Anhui, 230036, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Zoonoses of Anhui Province, Anhui Agricultural University, Hefei, Anhui, 230036, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Zoonoses of Anhui Province, Anhui Agricultural University, Hefei, Anhui, 230036, China.
authors.forename: Da-Gan
authors.initials: DG
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Zoonoses of Anhui Province, Anhui Agricultural University, Hefei, Anhui, 230036, China. Electronic address: yuwy@ahau.edu.cn.
authors.forename: Wei-Yi
authors.initials: WY
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000944:Antigens, Differentiation, B-Lymphocyte / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002347:Carps / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005260:Female; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008297:Male; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009928:Organ Specificity; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment / Q000662:veterinary
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D018076:DNA, Complementary; D029941:Fish Proteins; D000949:Histocompatibility Antigens Class II; D018832:Molecular Chaperones; D012333:RNA, Messenger; C045084:invariant chain
keywords: Association; Co-localization; Grass carp; Invariant chain; MHC