A Drosophila salivary gland mucin is also expressed in immune tissues: evidence for a function in coagulation and the entrapment of bacteria.
Our studies on the developmental regulation of glycosylation in Drosophila melanogaster led us to identify and characterize gp150, an ecdysone-regulated mucin that is found in hemocytes, the gut (peritrophic membrane) and in the salivary glands. We are particularly interested in mucin immune functions and found that gp150 is released from larval hemocytes, becomes part of the clot and participates in the entrapment of bacteria. By RT-PCR and RNAi experiments, we identified gp150 as the previously described I71-7, an ecdysone-induced salivary glue protein. We discuss the evolutionary and biochemical implications of the dual use of salivary proteins for immune functions in insects. Further molecular characterization of such shared proteins may enable a better understanding of the properties of proteins involved in containment and elimination of microbes, as well as hemostasis and wound repair.
Korayem
Ahmed M
AM
Department of Molecular Biology and Functional Genomics, Stockholm University, S-10691 Stockholm, Sweden.
Fabbri
Marco
M
Takahashi
Kuniaki
K
Scherfer
Christoph
C
Lindgren
Malin
M
Schmidt
Otto
O
Ueda
Ryu
R
Dushay
Mitchell S
MS
Theopold
Ulrich
U
D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000276:immunology; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D004440:Ecdysone / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D006031:Glycosylation; D006434:Hemocytes; D006458:Hemolymph; D007113:Immunity, Innate; D019476:Insect Proteins / Q000096:biosynthesis* / Q000502:physiology*; D007814:Larva / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000502:physiology*; D008969:Molecular Sequence Data; D009077:Mucins / Q000096:biosynthesis* / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012469:Salivary Glands / Q000378:metabolism
D029721:Drosophila Proteins; C499662:Gp150 protein, Drosophila; D019476:Insect Proteins; D008562:Membrane Glycoproteins; D009077:Mucins; D004440:Ecdysone