Adaptor protein is essential for insect cytokine signaling in hemocytes
スポンサーリンク
概要
- 論文の詳細を見る
Growth-blocking peptide (GBP) is an insect cytokine that stimulates a class of immune cells called plasmatocytes to adhere to each other and foreign surfaces. Although structure-activity studies have been extensively performed on the GBP and its mutants in Lepidoptera Pseudaletia separata, the signaling pathway of GBP-dependent activation of plasmatocytes remains unknown. We identified a novel adaptor protein (P77) with a molecular mass of 77 kDa containing SH2/SH3 domain binding motifs and an immunoreceptor tyrosine-based activation motif (ITAM)-like domain in the cytoplasmic region of the C-terminus. Although P77 did not show the capacity for direct binding with GBP, its cytoplasmic tyrosine residues were specifically phosphorylated within seconds after addition of GBP to a plasmatocyte suspension. Tyrosine phosphorylation of P77 was also observed when hemocytes were incubated with Enterobactor cloacae or Micrococcus luteus, but this phosphorylation was found to be induced by GBP released from hemocytes stimulated by the pathogens. We further detected tyrosine phosphorylation of the integrin β subunit in plasmatocytes stimulated by GBP. Double-stranded RNAs targeting P77 not only decreased GBP-dependent tyrosine phosphorylation of the integrin β subunit, but also abolished GBP-induced spreading of plasmatocytes on foreign surfaces. P77 RNAi larvae also showed significantly higher mortality than control larvae following infection with Serratia marcescens, thus indicating that P77 is essential for GBP to mediate a normal innate cellular immunity in insects. These results demonstrated that GBP signaling in plasmatocytes requires the adaptor protein P77 and that active P77-assisted tyrosine phosphorylation of integrins is critical for the activation of plasmatocytes.
- 2010-09-07
論文 | ランダム
- l30. 術後持続ドレーン排液バックカバーの改善を試みて
- 泌尿器科疾患の救急漢方 (特集 救急医療と漢方)
- 19.9.半導体製造装置(19.情報・精密機械)(機械工学年鑑)
- 19.10.半導体製造装置(19.情報・精密機械)(機械工学年鑑)
- 19.10 半導体製造装置(19.情報・精密機械)