title: Identification and characterization of a Ste20-like kinase in Artemia and its role in the developmental regulation and resistance to environmental stress.
abstract: BACKGROUND
  To adapt to extreme environments, the crustacean Artemia has evolved two alternative reproductive pathways. During ovoviviparous (direct) development, nauplius larvae are produced. In contrast, Artemia females release encysted diapause embryos (cysts) via the oviparous pathway. To date, the cellular mechanisms that regulate stress resistance of Artemia remain largely unknown. Ste20-like kinase (SLK) participates in multiple biological processes, including stress responses, apoptosis, and cell cycle progression.
  
  
  RESULTS
  We isolated and characterized a member of the SLK superfamily termed ArSLK from Artemia parthenogenetica. The ArSLK gene is transcribed throughout both ovoviviparous and oviparous development; however, the protein is located mainly in the nuclei of stress-resistant diapause cysts, unlike the nauplii and nauplius-destined embryos where it is cytoplasmic. Interestingly, exposure of nauplii to heat shock, acidic pH, and UV irradiation induced the translocation of ArSLK from cytoplasm to nucleus. This translocation was reversed following stress removal. Moreover, under physiologically-stressful conditions, the nauplius larvae produced by adults after gene knockdown of endogenous ArSLK by RNAi, lost the ability of free-swimming much earlier than those of control larvae from females injected with GFP dsRNA.
  
  
  CONCLUSIONS
  Taken together, this study demonstrated that trafficking of ArSLK between the cytoplasm and the nucleus participates in regulating the stress resistance of Artemia. Our findings may provide significant insight into the functions of members of the SLK superfamily.
authors.affiliation: Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Yu-Xia
authors.initials: YX
authors.lastname: Sun
authors.affiliation: Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Yang
authors.affiliation: Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001156:Artemia / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D004777:Environment; D005260:Female; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D018869:Heat-Shock Response / Q000235:genetics; D015151:Immunoblotting; D007814:Larva; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020539:Sequence Analysis, Protein; D013312:Stress, Physiological / Q000235:genetics; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D017346:Protein Serine-Threonine Kinases