Calcium and integrin-binding protein 1-like interacting with an integrin α-cytoplasmic domain facilitates cellular immunity in Helicoverpa armigera.

Integrins are transmembrane receptor heterodimers composed of α and ß subunits. They are known to mediate extracellular signals to promote cell adhesion and spreading, and are therefore essential for cellular immunity. However, proteins that bind to integrin cytoplasmic domains and mediate intracellular signaling to promote cell adhesion require identification. Calcium and integrin-binding protein 1 (CIB1) that binds to the integrin α-cytoplasmic domain has rarely been examined in insects. In this study, we found that 20-hydroxyecdysone promoted cell phagocytosis and spreading in Helicoverpa armigera. Transcriptomic analyses of hemocytes identified an integrin α gene (HaINTα-PS1) whose expression could be induced by either 20-hydroxyecdysone injection or bead challenge. Isothermal titration calorimetry assays showed that H. armigera CIB1-like (HaCIB1-like) weakly bound to the cytoplasmic domain of HaINTα-PS1 in the presence of calcium. HaINTα-PS1 or HaCIB1-like knockdown inhibited hemocytic encapsulation and phagocytosis, and plasmatocyte spreading. Moreover, HaCIB1-like overexpression in a H. armigera epidermal cell line overexpanded cells and impaired cell phagocytosis. Thus, insect CIB1-like potentially interacted with integrin α-cytoplasmic domain and facilitated cell adhesion. This study enriches our understanding of the molecular mechanism underlying integrin-mediated cellular immunity in insects.

A piggyBac-based TANGO GFP assay for high throughput screening of GPCR ligands in live cells.

BACKGROUND: GPCRs are considered essential for various physiological processes and have been the most productive drug targets. Therefore, development of the methods of GPCR ligands screening is a high priority for pharmaceutical industries and research institutions. METHODS: We developed a potential method (piggyBac-TANGO) based on the TANGO and PRESTO-TANGO assays. The system was optimized with a piggyBac transposon as a transgene vehicle, and eGFP was used as a reporter instead of luciferase. The assay was validated in the HEK 293T and U87-MG cell lines and antagonist activities of the compounds were assessed. The transgene copy number and long-term stability were evaluated by qPCR. Then, we performed a DRD2-targeted screening for natural products using the piggyBac-TANGO assay. RESULTS: The validation assay showed that using the piggyBac transposon as a transgene vehicle produced high signal-to-background ratio and stable readout confirmed by investigation of the transgene copy number and long-term stability. Use of eGFP instead of luciferase as a reporter enabled to create a high throughput system suitable for live cells. Moreover, the piggyBac-TANGO assay permitted versatile detection of antagonist activity of compounds and was not limited to a particular cell type. With the use of the piggyBac-TANGO assay, we have successfully identified a novel agonist of DRD2. CONCLUSION: Thus, the results indicate that the piggyBac-TANGO method is a user-friendly, robust and imaging-based assay that provides a novel approach to high throughput GPCR-targeted ligand screening and drug development.

catena-Poly[[(diaqua-calcium)-bis-(µ-2-fluorobenzoato)-1':1κO:O,O';1:1''κO,O':O] 2,2'-bipyridine hemi-solvate].

In the title compound, {[Ca(C(7)H(4)FO(2))(2)(H(2)O)(2)]·0.5C(10)H(8)N(2)}(n), the Ca(II) atom is coordinated by eigth O atoms from four 2-fluoro-benzoate ligands and two water mol-ecules, resulting in a distorted CaO(8) square-anti-prismatic coordination environment. The 2-fluoro-benzoate ligand bridges two symmetry-related Ca(II) atoms, giving rise to a chain structure extending along [100]. The distances between the Ca atom and its two symmetry-related counterparts are 4.054 (2) and 4.106 (2) Å. The polymeric chains are connected by classical O-H⋯N hydrogen bonds into a layer structure parallel to (010). The layers are connected by non-classical C-H⋯F hydrogen bonds into a three-dimensional supra-molecular structure. O-H⋯O and C-H⋯O inter-actions also occur. The uncoordinated 2,2'-bipyridine mol-ecule is located on a centre of symmetry at the mid-point of the bond between the two heterocycles. One of the two benzene rings is disordered over two sites with occupancy factors of 0.60 and 0.40.