Characterization of Integrin β1 and its effects on cell adhesion, migration and apoptosis in Sebastes schlegelii

Integrin β1, a transmembrane receptor, plays a pivotal role in regulating cell adhesion, migration, signal transduction, and apoptosis in diverse tissues and cell types. In this study, we identified integrin β1 from Sebastes schlegelii (SsITGβ1). The SsITGβ1 cDNA spans 4017 bp, including a 332 bp 5' untranslated region (UTR), a 1285 bp 3' UTR, and a 2400 bp open reading frame (ORF). The cytoplasmic tail contains two conserved motifs, NPIY and NPKY. Its protein comprises a signal peptide, an INB domain, an EGF-2 domain, an integrin-B-tail domain, a transmembrane domain, and an integrin-β-cyt domain. Phylogenetic and homology analyses revealed that integrin β1 is highly conserved among vertebrates. Tissue-specific expression analysis revealed that SsITGβ1 mRNA levels were highest in liver tissue. In the stimulation experiment of Edwardsiella piscicida, the expression of SsITGβ1 in spleen tissues changed significantly. Subcellular localization confirmed that SsITGβ1 is located in the cell membrane. Furthermore, in the S. schlegelii intestinal cell line, assays for cell-matrix adhesion, wound healing, and flow cytometry demonstrated that the overexpression of SsITGβ1 (via the plasmid pcDNA3.1-SsITGβ1) enhanced cell adhesion, promoted migration, and reduced apoptosis. In contrast, knockdown of SsITGβ1 using small interfering RNA resulted in the opposite effects. Analysis of mRNA changes in SsITGβ1-regulated genes indicated that SsITGβ1 may influence the aforementioned cellular activities via the FAK/ILK/RhoA and Bcl-2/IL-1β/TGF-β1 signaling pathways. This study offers a comprehensive characterization and functional analysis of integrin β1 in S. schlegelii, establishing a foundation for investigating its role in the regulatory mechanisms of immune responses and cellular activities.