Identification And Function Of Latrophilin-like Receptor In

G protein-coupled receptor (GPCR) is a superfamily of prtoteins in the cell membrane of organisms, which plays vital roles in the growth, development and reproduction. As a family-B GPCR, Latrophilin-like (LPHL) can pass exogenous spider toxin a-LTX signal thereby affecting their growth, development, adaptability and schizophrenia and other diseases occur in vertebrate. However, the information for the function and signal transeduction of insect LPHL is unclear. We use RNA interference (RNAi) to clarify the function and signal transduction system of LPHL in Tribolium castaneum.First of all, phylogenetic analysis was performed among49animals. The results revealed that animal lphl is originated from one ancentral gene, but this gene independently evolved among the vertebrate, Cephalochordata, Urochordata and insect. It is found that lphl has duplicated in vertebrates, and generated three copies (lphl-1, lphl-2and lphl-3), whereas lphl only contain two copied (lphl-2and lphl-3) in these animals such as Equus caballus, Gallus gallus, Taeniopygia guttata and Meleagris gallopavo. Complex evolutionary history was observed among Cephalochordata and Urochordata. lphl-2and lphl3were identified in Ciona intestinalis, Strongylocentrptus purpuratus、Branchiostoma floridae and Saccoglossus kowalevskii, but lphll and lphl-2were obtained from Caenorhabditis briggsae and Caenorhabditis elegans. Differing from these animals, there is only one lphl in the insect. Therefore, although animal lphl was derived from one ancestral gene, large differentiation has occurred among them, indicating that the function of this gene diverged among these animals.It is found that lphl shows the highest expression during the stage of late pupa in Tribolium castaneum, which is possibly associated with its important activities in the ecdysis. Inhibition of lphl at late larval stage resulted in significant lethal effect in Tribolium castaneum.26.7%of beetles died at the larval stage. Other insects show growth retardation in the pupal stage and fail to molt into adult,48.9%of them died at the pupal stage. Few of them that molt into adult have abnormal wings. These results demonstrate that lphl is essential for larval and pupal development in Tribolium castaneum. Furthermore, these larvae were treated with phoxim to explore whether the biological effects of LPHL in Tribolium castaneum are associated with neurotransmitter regulation. It is found that inhibition of lphl decreased the resistance to phoxim in Tribolium castaneum, but up-regulated Acetylcholine esterase (TC014402) expression, suggesting that this activity is transduced by Acetylcholine esterase. Another finding of this study is that inhibition of lphl up-regulated the expressions of pka, pi3k, askl, jnk, speculated that effects of lphl on the growth and development in Tribolium castaneum were transduced by these signal pathways. To further understand the function and signal transduction of LPHL from protein, method of differential proteomics was used to compare and analyze two-dimensional electrophoresis maps of RNAi and control groups, and found that larval proteins are widely distributed in the PH5-8and14.4-116.0KD; totally,111points of different protein were found, indicating that suppression of lphl resulted in significant difference in protein level. Subsequently, these points of difference will be identified by mass spectrum.