The Transmembrane Adaptor Protein SCIMP Facilitates Sustained Dectin-1 Signaling in Dendritic Cells

0472003 - ÚMG 2017 RIV US eng J - Journal Article
Králová, Jarmila - Fabišik, Matěj - Pokorná, Jana - Skopcová, Tereza - Malissen, B. - Brdička, Tomáš
The Transmembrane Adaptor Protein SCIMP Facilitates Sustained Dectin-1 Signaling in Dendritic Cells.
Journal of Biological Chemistry. Roč. 291, č. 32 (2016), s. 16530-16540. ISSN 0021-9258. E-ISSN 1083-351X
R&D Projects: GA ČR GAP302/12/1712
Institutional support: RVO:68378050
Keywords : beta-glucan receptor * c-type lectin * toll-like receptors * fungal-infections * antifungal immunity * pattern-recognition * candida-albicans * erk activation * mice * innate
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 4.125, year: 2016

Transmembrane adaptor proteins are molecules specialized in recruiting cytoplasmic proteins to the proximity of the cell membrane as part of the signal transduction process. A member of this family, SLP65/SLP76, Csk-interacting membrane protein (SCIMP), recruits a complex of SLP65/SLP76 and Grb2 adaptor proteins, known to be involved in the activation of PLC gamma 1/2, Ras, and other pathways. SCIMP expression is restricted to antigen-presenting cells. In a previous cell line-based study, it was shown that, in B cells, SCIMP contributes to the reverse signaling in the immunological synapse, downstream of MHCII glycoproteins. There it mainly facilitates the activation of ERK MAP kinases. However, its importance for MHCII glycoprotein-dependent ERK signaling in primary B cells has not been analyzed. Moreover, its role in macrophages and dendritic cells has remained largely unknown. Here we present the results of our analysis of SCIMP-deficient mice. In these mice, we did not observe any defects in B cell signaling and B cell-dependent responses. On the other hand, we found that, in dendritic cells and macrophages, SCIMP expression is up-regulated after exposure to GM-CSF or the Dectin-1 agonist zymosan. Moreover, we found that SCIMP is strongly phosphorylated after Dectin-1 stimulation and that it participates in signal transduction downstream of this important pattern recognition receptor. Our analysis of SCIMP-deficient dendritic cells revealed that SCIMP specifically contributes to sustaining long-term MAP kinase signaling and cytokine production downstream of Dectin-1 because of an increased expression and sustained phosphorylation lasting at least 24 h after signal initiation.
Permanent Link: http://hdl.handle.net/11104/0269362