[Structure and function of BmIntegrin β2 in silkworm, Bombyx mori]

Integrins are cell adhesion receptors, which consists of several transmembrane glycoproteins. They are widely distributed on the cell surface and involved in signal transduction pathways. As a heterodimer, each integrin is composed of one α subunit and one β subunit. Integrins are mainly expressed on lepidopteran hemocytes and involved in cell immune response. The full-length cDNA sequence of BmIntegrin β2 was obtained by PCR and RACE, including 2 434 bp. BmIntegrin β2 was predicted to be a transmembrane protein. The BmIntegrin β2 expression profile was detected by qRT-PCR at L4D3 or L5D3 larval stage, and it was highly expressed in hemocyte and hematopoietic organ. Anti-BmIntegrin β2 polyclonal antibody was generated following prokaryotic expression, protein purification and animal immunization, which is highly specific and effective for recognizing BmIntegrin β2 protein through Western blotting. The results of plasmatocytes adhesion experiment showed that BmIntegrin β2 plays an important role on the adhesion and spreading of plasmatocytes to foreign surfaces. This study provides a foundation for further research of the biological function of BmIntegrin β2 gene.