Screening of proteins interacting with the bacterial-origin horizontal transferred serine/threonine-protein kinase in Pacific white shrimp Litopenaeus vannamei.

Litopenaeus vannamei is an economically important cultured shrimp worldwide, while frequent disease outbreaks restrict the development of its aquaculture. Pathogen-host horizontal gene transfer (HGT) provides new insights into improving shrimp disease resistance. The proto-oncogene serine/threonine-protein kinase mos-like (LvSTK) is a bacterial-derived horizontally transferred gene (HTG) identified in the L. vannamei genome. In the present study, yeast two-hybrid (Y2H) technology was employed to screen for proteins interacting with LvSTK in L. vannamei. A total of 28 independent positive interaction clones were ultimately identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that these potential interacting proteins are involved in multiple biological processes, including immune response, disease regulation, cell growth and apoptosis, material transport and catabolism, as well as signal transduction. Ten potential interacting proteins were selected for pairwise validation and dot plate assay, and the results confirmed that 8 of them could all interact with LvSTK. Notably, peritrophin-1-like, β-actin, amylase, and other proteins are closely associated with immune regulation. These interacting proteins provide an important reference for elucidating the biological function of LvSTK and revealing the molecular mechanisms underlying the regulation of shrimp infection.