A vector whitefly endocytic receptor facilitates the entry of begomoviruses into its midgut cells via binding to virion capsid proteins

PLoS Pathog. 2020 Dec 3;16(12):e1009053. doi: 10.1371/journal.ppat.1009053. eCollection 2020 Dec.

Abstract

Many circulative plant viruses transmitted by insect vectors are devastating to agriculture worldwide. The midgut wall of vector insects represents a major barrier and at the same time the key gate a circulative plant virus must cross for productive transmission. However, how these viruses enter insect midgut cells remains poorly understood. Here, we identified an endocytic receptor complex for begomoviruses in the midgut cells of their whitefly vector. Our results show that two whitefly proteins, BtCUBN and BtAMN, compose a receptor complex BtCubam, for which BtCUBN contributes a viral-binding region and BtAMN contributes to membrane anchorage. Begomoviruses appear to be internalized together with BtCubam via its interaction with the 12-19 CUB domains of BtCUBN via clathrin-dependent endocytosis. Functional analysis indicates that interruption of BtCUBN and BtAMN lead to reduction of virus acquisition and transmission by whitefly. In contrast, CUBN-begomovirus interaction was not observed in two non-competent whitefly-begomovirus combinations. These observations suggest a major role of the specific endocytic receptor in facilitating viral entry into vector midgut cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Begomovirus / metabolism*
  • Begomovirus / pathogenicity
  • Capsid Proteins / metabolism
  • Digestive System / metabolism
  • Digestive System / virology
  • Drosophila Proteins / metabolism
  • Endocytosis / physiology
  • Hemiptera / metabolism
  • Hemiptera / virology*
  • Insect Vectors / metabolism
  • Insect Vectors / virology
  • Neuropeptides / metabolism
  • Plant Diseases / virology
  • Plant Viruses
  • Receptors, Cell Surface / metabolism
  • Virion / metabolism

Substances

  • Capsid Proteins
  • Cubn protein, Drosophila
  • Drosophila Proteins
  • Neuropeptides
  • Receptors, Cell Surface
  • amn protein, Drosophila

Grants and funding

Financial supports for this study were provided by the National Natural Science Foundation of China (http://www.nsfc.gov.cn) to SSL (Project no: 31930092) and National Natural Science Foundation of China (http://www.nsfc.gov.cn) to XWW (Project no: 31925033). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.