Molecular characterization and expression of AMP-activated protein kinase in response to low-salinity stress in the Pacific white shrimp Litopenaeus vannamei.
AMP-activated protein kinase (AMPK) serves as a major regulator of cellular energy metabolism by activating ATP production pathways and blocking ATP consumption. However, information on AMPK genes in aquatic animals is limited. In this study, three subunits of AMPK were cloned from the Pacific white shrimp Litopenaeus vannamei. The full-length cDNAs of the α, β and γ subunits were 1617, 1243 and 3467bp long, respectively, with open reading frames of 1566, 873 and 2988bp encoding for 521, 290 and 996 amino acids, respectively. Amino acid sequence alignments of the three subunits showed that the functional domains in the L. vannamei proteins retained the highest similarity with those of other animals, at 89%, 58%, and 75%, respectively. The expression levels of the three subunits were higher in the muscle and gills than in the eyestalk and hepatopancreas. The mRNA levels of AMPK-α and AMPK-β were up-regulated in the hepatopancreas and muscle after acute low-salinity stress at 3psu for 6h compared with control salinity at 20psu. After 8-week salinity stress at 3psu, AMPK-α and AMPK-β mRNA levels in the hepatopancreas were significantly higher than those of the control at 30psu. However, in the muscle only AMPK-γ mRNA was significantly up-regulated at low salinity relative to controls. Muscle and hepatopancreas showed increases in AMPK protein after 6h exposure to low salinity, but there were no differences seen after long term acclimation. The change patterns of protein were slightly differing from the mRNA patterns due to the distinguishing function of individual subunits of AMPK. These findings confirm that three AMPK subunits are present in L. vannamei and that all encode proteins with conserved functional domains. The three AMPK subunits are all regulated at the transcriptional and protein levels to manage excess energy expenditure during salinity stress.
Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai 200241, China.
Chang
C
Xu
Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai 200241, China. Electronic address: ecli@bio.ecnu.edu.cn.
Erchao
E
Li
Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai 200241, China.
Zhixin
Z
Xu
Department of Aquaculture, Hainan University, Haikou, Hainan 570228, China.
Shifeng
S
Wang
Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai 200241, China.
Ke
K
Chen
Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai 200241, China.
Xiaodan
X
Wang
Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai 200241, China.
Tongyu
T
Li
School of Biological Sciences, Flinders University, Adelaide, SA 5001, Australia.
Jian G
JG
Qin
Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, 500 Dongchuan Rd., Shanghai 200241, China. Electronic address: lqchen@bio.ecnu.edu.cn.
Liqiao
L
Chen
D055372:AMP-Activated Protein Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004734:Energy Metabolism; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D009928:Organ Specificity; D033561:Penaeidae / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D054712:Salinity; D013312:Stress, Physiological / Q000235:genetics*; D013997:Time Factors; D014158:Transcription, Genetic
D055372:AMP-Activated Protein Kinases
AMP-activated protein kinase; AMPK content; Energy metabolism; Gene expression; Litopenaeus vannamei; Salinity