Gut plasma membrane proteomes of adults and larvae of the European honey bee, Apis mellifera

The European honey bee, Apis mellifera, is a vital pollinator of agricultural and horticultural crops. The midgut is the site of entry for honey bee pathogens and for bacterial pesticidal proteins (BPP) used for crop protection. We characterized the proteome of brush border membrane vesicles (BBMV), which are enriched in gut surface proteins, prepared from the midguts of honey bee adults and larvae. A total of 2064 and 2337 proteins were identified via timsTOF mass spectrometry in midgut BBMV from adults and larvae, respectively. These proteins included 71 midgut plasma membrane proteins in adult and 77 in larval samples identified by use of bioinformatic tools and manual curation. The most abundant proteins were identified using a new hybrid method that takes both protein length and sample complexity into account. The potential roles of plasma membrane proteins in interaction with and defense against pathogens were assessed by use of Gene Ontology terms. Seven proteins from three of the protein families (aminopeptidase, cadherin, ATP-binding cassette transporter subfamily C) known to include functional BPP receptors in other insects were identified. Information on the presence and relative abundance of these proteins could inform the risk of BPP toxicity to honey bees.