A novel ATP-binding cassette protein (NoboABCG1.3) p lays a vital role in the proliferation of Nosema bombycis

ATP-binding cassette (ABC) transporter proteins, one of the largest families of membrane transport proteins, participate in almost all biological processes and widely exist in living organisms. Microsporidia are intracellular parasites, they can reduce crop yields and pose a threat to human health. The ABC proteins are also present in microsporidia and plays a critical role in their proliferation and energy transport. In this study, a novel ABC transporter protein of Nosema bombycis named NoboABCG1.3 was identified. The NoboABCG1.3 protein is comprised of 640 amino acids, which contains six transmembrane domains and one nucleotide-binding domain. After N. bombycis infection of cells or tissues, quantitative reverse transcription polymerase chain reaction analysis revealed a progressive elevation in the transcript levels of NoboABCG1.3 . Downregulation of NoboABCG1.3 expression significantly inhibited N. bombycis proliferation. Subsequently, a transgenic cell line stably expressing an interfering fragment of NoboABCG1.3 was established, which exhibited extreme inhibition on the proliferation of N. bombycis . These findings indicate that NoboABCG1.3 plays a crucial role in the proliferation of N. bombycis and holds promise as a target for developing N. bombycis -resistant silkworms.