Premium
Hypersensitivity of Vps33B mutant flies to non‐pathogenic infections is dictated by aberrant activation of p38b MAP kinase
Author(s) -
Zhang Jian,
Tracy Charles,
Pasare Chandrashekhar,
Zeng Jinsheng,
Krämer Helmut
Publication year - 2020
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/tra.12756
Subject(s) - biology , microbiology and biotechnology , innate immune system , mapk/erk pathway , protein kinase a , receptor , signal transduction , p38 mitogen activated protein kinases , proinflammatory cytokine , downregulation and upregulation , map kinase kinase kinase , scaffold protein , kinase , immunology , inflammation , biochemistry , gene
Loss of the arthrogryposis‐renal dysfunction‐cholestasis (ARC) syndrome‐linked Vps33B protein results in exaggerated inflammatory responses upon activation of receptors of the innate immune system in both vertebrates and flies. However, little is known about the signaling elements downstream of these receptors that are critical for the hypersensitivity of Vps33B mutants. Here, we show that p38b MAP kinase contributes to the enhanced inflammatory responses in flies lacking Vps33B . Loss of p38b mitogen‐activated protein kinase (MAPK) reduces enhanced inflammatory responses and prolongs the survival of infected Vps33B deficient flies. The function of p38 MAPK is not limited to its proinflammatory effects downstream of the PGRP‐LC receptor as p38 also modulates endosomal trafficking of PGRP‐LC and phagocytosis of bacteria. Expression of constitutively active p38b MAPK, but not dominant negative p38b MAPK enhances accumulation of endocytosed PGRP‐LC receptors or phagocytosed bacteria within cells. Moreover, p38 MAPK is required for induction of macropinocytosis, an alternate pathway for the downregulation of immune receptors. Together, our data indicate that p38 MAPK activates multiple pathways that can contribute to the dysregulation of innate immune signaling in ARC syndrome.