title: Adenylate kinase 2 (AK2) promotes cell proliferation in insect development.
abstract: BACKGROUND
  Adenylate kinase 2 (AK2) is a phosphotransferase that catalyzes the reversible reaction 2ADP(GDP) ↔ ATP(GTP) + AMP and influences cellular energy homeostasis. However, the role of AK2 in regulating cell proliferation remains unclear because AK2 has been reported to be involved in either cell proliferation or cell apoptosis in different cell types of various organisms.
  
  
  RESULTS
  This study reports AK2 promotion of cell proliferation using the lepidopteran insect Helicoverpa armigera and its epidermal cell line HaEpi as models. Western blot analysis indicates that AK2 constitutively expresses in various tissues during larval development. Immunocytochemistry analysis indicates that AK2 localizes in the mitochondria. The recombinant expressed AK2 in E. coli promotes cell growth and viability of HaEpi cell line by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. AK2 knockdown in larvae by RNA interference causes larval growth defects, including body weight decrease and development delay. AK2 knockdown in larvae also decreases the number of circulating haemocytes. The mechanism for such effects might be the suppression of gene transcription involved in insect development caused by AK2 knockdown.
  
  
  CONCLUSIONS
  These results show that AK2 regulates cell growth, viability, and proliferation in insect growth and development.
authors.affiliation: The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong University, Shandong, Jinan, 250100, China.
authors.forename: Ru-Ping
authors.initials: RP
authors.lastname: Chen
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Liu
authors.forename: Hong-Lian
authors.initials: HL
authors.lastname: Shao
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Zheng
authors.forename: Jin-Xing
authors.initials: JX
authors.lastname: Wang
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Zhao
mesh_terms: D000263:Adenylate Kinase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D007814:Larva / Q000187:drug effects / Q000502:physiology; D007915:Lepidoptera / Q000254:growth & development; D008928:Mitochondria / Q000201:enzymology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
chemical_list: D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D000263:Adenylate Kinase; C110938:adenylate kinase 2