Coronin-1 is phosphorylated at Thr-412 by protein kinase Cα in human phagocytic cells.
Biochem Biophys Rep 2021;
27:101041. [PMID:
34189278 PMCID:
PMC8220002 DOI:
10.1016/j.bbrep.2021.101041]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/17/2021] [Accepted: 05/31/2021] [Indexed: 11/25/2022] Open
Abstract
Coronin-1, a hematopoietic cell-specific actin-binding protein, is thought to be involved in the phagocytic process through its interaction with actin filaments. The dissociation of coronin-1 from phagosomes after its transient accumulation on the phagosome surface is associated with lysosomal fusion. We previously reported that 1) coronin-1 is phosphorylated by protein kinase C (PKC), 2) coronin-1 has two phosphorylation sites, Ser-2 and Thr-412, and 3) Thr-412 of coronin-1 is phosphorylated during phagocytosis. In this study, we examined which PKC isoform is responsible for the phosphorylation of coronin-1 at Thr-412 by using isotype-specific PKC inhibitors and small interfering RNAs (siRNAs). Thr-412 phosphorylation of coronin-1 was suppressed by Gö6976, an inhibitor of PKCα and PKCβI. This phosphorylation was attenuated by siRNA for PKCα, but not by siRNA for PKCβ. Furthermore, Thr-412 of coronin-1 was phosphorylated by recombinant PKCα in vitro, but not by recombinant PKCβ. We next examined the effects of Gö6976 on the intracellular distribution of coronin-1 in HL60 cells during phagocytosis. The confocal fluorescence microscopic observation showed that coronin-1 was not dissociated from phagosomes in Gö6976-treated cells. These results indicate that phosphorylation of coronin-1 at Thr-412 by PKCα regulates intracellular distribution during phagocytosis.
Phosphorylation of coronin-1 at Thr-412 is suppressed by PKCα/β inhibitor.
PKCα not PKCβ phosphorylates coronin-1 at Thr-412 in vitro.
Dissociation of coronin-1 from phagosome is regulated by PKCα.
Phosphorylation of coronin-1 at Thr-412 may trigger phagosome maturation.
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