Adenylate kinase 2 (AK2) promotes cell proliferation in insect development

Ru-Ping Chen,Jin-Xing Wang,Wei-Wei Zheng,Chun-Yan Liu,Hong-Lian Shao,Xiao-Fan Zhao

doi:10.1186/1471-2199-13-31

Ru-Ping Chen, Jin-Xing Wang + Show 4 more

Open Access

https://doi.org/10.1186/1471-2199-13-31

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Abstract

BackgroundAdenylate 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.ResultsThis 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.ConclusionThese results show that AK2 regulates cell growth, viability, and proliferation in insect growth and development.

Highlights

Adenylate kinase 2 (AK2) is a phosphotransferase that catalyzes the reversible reaction 2ADP(GDP) ↔ ATP(GTP) + AMP and influences cellular energy homeostasis
A recent study reveals that the homozygous AK2 (−/−) larvae of Drosophila melanogaster ceases growth and causes death before reaching the third instar larval stage, indicating that AK2 is necessary for the growth and development of D. melanogaster [11]
The pupation time in the larvae that fed on dsAK2 delayed about 3 days compared the control (Figure 4C). These results suggest that AK2 is necessary for larval growth and development

Summary

Introduction

Adenylate kinase 2 (AK2) is a phosphotransferase that catalyzes the reversible reaction 2ADP(GDP) ↔ ATP(GTP) + AMP and influences cellular energy homeostasis. Adenylate kinase (AK or ADK) is a phosphotransferase that catalyzes the reversible reaction 2ADP(GDP) ↔ ATP(GTP) + AMP in the presence of Mg2+ and influences cellular energy homeostasis and cellular adenine nucleotide metabolism [1,2]. Prokaryotic cells [3] and eukaryotic yeasts [4] have a single-type gene of AK essential for their survival, which indicates the significance of AK in energy metabolism. The knockdown of zebra fish AK2, the only type of AK in leukocytes, causes leukocyte development defects, indicating the importance of AK2 in leukocyte differentiation [10]. A recent study reveals that the homozygous AK2 (−/−) larvae of Drosophila melanogaster ceases growth and causes death before reaching the third instar larval stage, indicating that AK2 is necessary for the growth and development of D. melanogaster [11]

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