title: A novel MKK gene (AjMKK3/6) in the sea cucumber Apostichopus japonicus: Identification, characterization and its response to pathogenic challenge.
abstract: The mitogen-activated protein kinase kinases (MKKs) are key components of MAP kinase (MAPK) cascades and function as redox-regulated signaling factors in pathological and physiological processes. In this study, we identified a novel MKK3/6 gene in the sea cucumber Apostichopus japonicus (designated as AjMKK3/6) by transcriptome database mining and rapid amplification of cDNA ends (RACE) approaches. Sequence analysis and protein structure prediction showed that AjMKK3/6 is highly conserved as compared to those from other invertebrate and vertebrate species. Molecular phylogeny result revealed that AjMKK3/6 exhibited a closest relationship with that from Strongylocentrotus purpuratus. Quantitative real-time PCR was employed to determine the expression profiles of AjMKK3/6 in healthy adult A. japonicus tissues and in coelomocytes after Vibrio splendidus infection in vivo, respectively. As results shown, AjMKK3/6 was ubiquitously expressed in all examined tissues of healthy adult A. japonicus with a relative expression level from high to low as body wall > tube feet > coelomocytes > respiratory tree > intestine > longitudinal muscle. Significant expression changes of AjMKK3/6 in coelomocytes were observed at 12 h- and 72 h-after V. splendidus infection, respectively. In general, the current study will enrich our knowledge of characterizations and immno-functions of MKK3/6 in sea cucumbers.
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, Liaoning, 116023, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, Liaoning, 116023, PR China.
authors.forename: Ge
authors.initials: G
authors.lastname: Chen
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, Liaoning, 116023, PR China.
authors.forename: Kaiquan
authors.initials: K
authors.lastname: Li
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, Liaoning, 116023, PR China.
authors.forename: Jingxian
authors.initials: J
authors.lastname: Sun
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, Liaoning, 116023, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Song
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, Liaoning, 116023, PR China. Electronic address: zyydlou@hotmail.com.
authors.forename: Yaoyao
authors.initials: Y
authors.lastname: Zhan
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, Liaoning, 116023, PR China.
authors.forename: Xiangxiang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, Liaoning, 116023, PR China.
authors.forename: Limeng
authors.initials: L
authors.lastname: Yang
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, Liaoning, 116023, PR China. Electronic address: yqkeylab@hotmail.com.
authors.forename: Yaqing
authors.initials: Y
authors.lastname: Chang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D007113:Immunity, Innate; D020929:Mitogen-Activated Protein Kinase Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008968:Molecular Conformation; D010802:Phylogeny; D017433:Protein Structure, Secondary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D047528:Stichopus / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D014733:Vibrio / Q000502:physiology*
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D020929:Mitogen-Activated Protein Kinase Kinases
keywords: Apostichopus japonicus; Expression analysis; Mitogen-activated protein kinase kinase 3/6; Vibrio splendidus infection