In:
Journal of Leukocyte Biology, Oxford University Press (OUP), Vol. 94, No. 1 ( 2013-05-13), p. 109-122
Abstract:
In RAW 264.7 cells [1], PKC-ɛ regulates FcγR-mediated phagocytosis. BMDM behave similarly; PKC-ɛ concentrates at phagosomes and internalization are reduced in PKC-ɛ−/− cells. Two questions were asked: what is the role of PKC-ɛ? and what domains are necessary for PKC-ɛ concentration? Function was studied using BMDM and frustrated phagocytosis. On IgG surfaces, PKC-ɛ−/− macrophages spread less than WT. Patch-clamping revealed that the spreading defect is a result of the failure of PKC-ɛ−/− macrophages to add membrane. The defect is specific for FcγR ligation and can be reversed by expression of full-length (but not the isolated RD) PKC-ɛ in PKC-ɛ−/− BMDM. Thus, PKC-ɛ function in phagocytosis requires translocation to phagosomes and the catalytic domain. The expression of chimeric PKC molecules in RAW cells identified the ɛPS as necessary for PKC-ɛ targeting. When placed into (nonlocalizing) PKC-δ, ɛPS was sufficient for concentration, albeit to a lesser degree than intact PKC-ɛ. In contrast, translocation of δ(ɛPSC1B) resembled that of WT PKC-ɛ. Thus, ɛPS and ɛC1B cooperate for optimal phagosome targeting. Finally, cells expressing ɛK437W were significantly less phagocytic than their PKC-ɛ-expressing counterparts, blocked at the pseudopod-extension phase. In summary, we have shown that ɛPS and ɛC1B are necessary and sufficient for targeting PKC-ɛ to phagosomes, where its catalytic activity is required for membrane delivery and pseudopod extension.
Type of Medium:
Online Resource
ISSN:
0741-5400
,
1938-3673
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2013
detail.hit.zdb_id:
2026833-6
SSG:
12
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