TWO INNEXINS OF Spodoptera litura INFLUENCES HEMICHANNEL AND GAP JUNCTION FUNCTIONS IN CELLULAR IMMUNE RESPONSES.
Insect cellular immune responses include encapsulation, nodule formation, and phagocytosis. Hemichannels and gap junctions are involved in these cellular actions. Innexins (Inxs: analogous to the vertebrate connexins) form hemichannels and gap junctions, but the molecular mechanisms underlying their biology is still unclear. In this article, we reported a steady-state level of Inxs (SpliInxs) in hemocytes of Spodoptera litura, which formed nonfunctional hemichannels on the cell surface to maintain normal metabolism. We also reported that two innnexins (SpliInx2 and SpliInx3) were expressed significantly higher in hemocytes compared to other tissues, suggesting that they play important roles in hemocytes. Amino acid analysis found that two cysteine residues in two extracellular loops provided the capability for SpliInx2 and SpliInx3 hemichannels to dock into gap junctions. Western blotting demonstrated that both extracellular and intracellular loops of SpliInx3 and the extracellular loops of SpliInx2 might undergo posttranslational modification during the formation of a steady-state hemichannel. During hemichannel formation, SpliInx2 presented as one isoform, while SpliInx3 presented as three isoforms. These results provide fundamental knowledge for further study of how steady-state levels of SpliInxs are dynamically adjusted to perform cellular immune responses under immune challenge.
School of Life Sciences and Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P. R., China.
Zunyu
Z
Pang
School of Life Sciences and Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P. R., China.
Ming
M
Li
School of Life Sciences and Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P. R., China.
Dongshuai
D
Yu
School of Life Sciences and Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P. R., China.
Zhang
Z
Yan
School of Life Sciences and Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P. R., China.
Xinyi
X
Liu
School of Life Sciences and Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P. R., China.
Xinglai
X
Ji
School of Life Sciences and Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P. R., China.
Yang
Y
Yang
School of Life Sciences and Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P. R., China.
Jiansheng
J
Hu
School of Life Sciences and Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, P. R., China.
Kaijun
K
Luo
D000595:Amino Acid Sequence; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D017630:Connexins / Q000378:metabolism*; D017629:Gap Junctions / Q000378:metabolism*; D006434:Hemocytes / Q000166:cytology / Q000276:immunology*; D007111:Immunity, Cellular; D019476:Insect Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D018411:Spodoptera / Q000276:immunology* / Q000469:parasitology
D017630:Connexins; D019476:Insect Proteins
Cysteine residue; cellular immune response; gap junction protein; innexin; posttranslational modification