Glucose-regulated protein 78 regulates the subunit-folding of the CCT complex by modulating gene expression and protein interaction in the microsporidian Nosema bombycis

Sheng Xu; Shengyan Xiao; Jingru Qi; Mingshuai Yao; Ping He; Runpeng Wang; Erjun Wei; Qiang Wang; Yiling Zhang; Xudong Tang; Zhongyuan Shen

doi:10.1016/j.ijbiomac.2024.138971

Glucose-regulated protein 78 regulates the subunit-folding of the CCT complex by modulating gene expression and protein interaction in the microsporidian Nosema bombycis

Int J Biol Macromol. 2024 Dec 19:290:138971. doi: 10.1016/j.ijbiomac.2024.138971. Online ahead of print.

Authors

Affiliations

¹ Jiangsu University of Science and Technology, Zhenjiang, People's Republic of China.
² Jiangsu University of Science and Technology, Zhenjiang, People's Republic of China; Sericulture Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, People's Republic of China.
³ Jiangsu University of Science and Technology, Zhenjiang, People's Republic of China; Sericulture Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, People's Republic of China. Electronic address: szysri@163.com.

PMID: 39708871
DOI: 10.1016/j.ijbiomac.2024.138971

Abstract

Chaperonin containing tailless complex polypeptide 1 (CCT) functions as a molecular chaperone and is essential for ensuring proper protein folding. Glucose-regulated protein 78 (GRP78/Bip), also a type of chaperone, not only assists in folding of proteins, but also facilitates the transportation of proteins into the endoplasmic reticulum (ER) via the Sec protein complex. In this study, we identified the CCTη of N. bombycis (NbCCTη) for the first time. Immunoprecipitations and mass spectrometry (IP-MS) of NbCCTη analysis showed that NbBip may interact with CCT subunits. Yeast two-hybrid assays validated that NbBip interacts with NbCCTη, as well as NbCCTα and NbCCTε. Furthermore, RNA interference on NbBip brought about radical expression of NbCCTα, NbCCTε, and NbCCTη, while RNAi on NbCCT subunits resulted in abnormal expression of NbBip. Immunofluorescence assay results showed that NbBip colocalized with NbCCTα and NbCCTη, and CCTη colocalized with Nbβ-tubulin and Nbactin in the parasite. Collectively, these findings suggest that NbBip may act as a crucial factor in the subunit-folding and assembly of CCT complex in N. bombycis.

Keywords: Bip (GRP78); CCT complex; Immunolocalization; Interaction; Microsporidia; Nosema bombycis.