Features and mechanisms of propofol-induced protein kinase C (PKC) translocation and activation in living cells

Soma Noguchi; Taketoshi Kajimoto; Takuya Kumamoto; Masashi Shingai; Soshi Narasaki; Tomoaki Urabe; Serika Imamura; Kana Harada; Izumi Hide; Sigeru Tanaka; Yuhki Yanase; Shun-Ichi Nakamura; Yasuo M Tsutsumi; Norio Sakai

doi:10.3389/fphar.2023.1284586

Features and mechanisms of propofol-induced protein kinase C (PKC) translocation and activation in living cells

Front Pharmacol. 2023 Nov 7:14:1284586. doi: 10.3389/fphar.2023.1284586. eCollection 2023.

Authors

Affiliations

¹ Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
² Division of Biochemistry, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan.
³ Department of Synthetic Organic Chemistry, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
⁴ Department of Anesthesiology and Critical Care, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
⁵ Department of Dental Anesthesiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
⁶ Department of Pharmacotherapy, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.

Abstract

Background and purpose: In this study, we aimed to elucidate the action mechanisms of propofol, particularly those underlying propofol-induced protein kinase C (PKC) translocation. Experimental approach: Various PKCs fused with green fluorescent protein (PKC-GFP) or other GFP-fused proteins were expressed in HeLa cells, and their propofol-induced dynamics were observed using confocal laser scanning microscopy. Propofol-induced PKC activation in cells was estimated using the C kinase activity receptor (CKAR), an indicator of intracellular PKC activation. We also examined PKC translocation using isomers and derivatives of propofol to identify the crucial structural motifs involved in this process. Key results: Propofol persistently translocated PKCα conventional PKCs and PKCδ from novel PKCs (nPKCs) to the plasma membrane (PM). Propofol translocated PKCδ and PKCη of nPKCs to the Golgi apparatus and endoplasmic reticulum, respectively. Propofol also induced the nuclear translocation of PKCζ of atypical PKCs or proteins other than PKCs, such that the protein concentration inside and outside the nucleus became uniform. CKAR analysis revealed that propofol activated PKC in the PM and Golgi apparatus. Moreover, tests using isomers and derivatives of propofol predicted that the structural motifs important for the induction of PKC and nuclear translocation are different. Conclusion and implications: Propofol induced the subtype-specific intracellular translocation of PKCs and activated PKCs. Additionally, propofol induced the nuclear translocation of PKCs and other proteins, probably by altering the permeability of the nuclear envelope. Interestingly, propofol-induced PKC and nuclear translocation may occur via different mechanisms. Our findings provide insights into the action mechanisms of propofol.

Keywords: anesthetic; intracellular organelle; nuclear translocation of proteins; propofol; propofol derivatives; protein kinase C (PKC).

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by Grants-in-Aid for Scientific Research from the Ministry of Education, Sports, and Culture of Japan (JSPS KAKENHI; grant numbers 19H03409, 21K06802, 21K16560, and 22K06862). This study was also supported by grants from the Takeda Science Foundation and Uehara Memorial Foundation. This study was performed using equipment at the Radiation Research Center for frontier Science and Natural Science Center for Basic Research and Development, Hiroshima University.