ZSWIM8 is a myogenic protein that partly prevents C2C12 differentiation

Fumihiko Okumura,Rio Ikuta,Shun Hamada,Naoki Hisamoto,Taichi Hara,Nodoka Oki,Yuha Fujiki,Kunio Nakatsukasa,Kana Osaki,Takumi Kamura

doi:10.1038/s41598-021-00306-6

Abstract

Cell adhesion molecule-related/downregulated by oncogenes (Cdon) is a cell-surface receptor that mediates cell–cell interactions and positively regulates myogenesis. The cytoplasmic region of Cdon interacts with other proteins to form a Cdon/JLP/Bnip-2/CDC42 complex that activates p38 mitogen-activated protein kinase (MAPK) and induces myogenesis. However, Cdon complex may include other proteins during myogenesis. In this study, we found that Cullin 2-interacting protein zinc finger SWIM type containing 8 (ZSWIM8) ubiquitin ligase is induced during C2C12 differentiation and is included in the Cdon complex. We knocked-down Zswim8 in C2C12 cells to determine the effect of ZSWIM8 on differentiation. However, we detected neither ZSWIM8-dependent ubiquitination nor the degradation of Bnip2, Cdon, or JLP. In contrast, ZSWIM8 knockdown accelerated C2C12 differentiation. These results suggest that ZSWIM8 is a Cdon complex-included myogenic protein that prevents C2C12 differentiation without affecting the stability of Bnip2, Cdon, and JLP.

Highlights

Cell adhesion molecule-related/downregulated by oncogenes (Cdon) is a cell-surface receptor that mediates cell–cell interactions and positively regulates myogenesis
zinc finger SWIM type containing 8 (ZSWIM8) knockdown increased the expression of myosin heavy chain (MHC) and myogenin compared with that in control cells, indicating that ZSWIM8 prevents the differentiation of C2C12 cells (Fig. 1B and C, and Supplementary Fig. 1)
ZSWIM8 was induced after 1 day of differentiation, and MHC and myogenin were detectable after 1–2 days of differentiation in the control knockdown cells as in the generally utilized C2C12 cells (Supplementary Fig. 2A)

Summary

Introduction

Cell adhesion molecule-related/downregulated by oncogenes (Cdon) is a cell-surface receptor that mediates cell–cell interactions and positively regulates myogenesis. The cytoplasmic region of Cdon interacts with other proteins to form a Cdon/JLP/Bnip-2/CDC42 complex that activates p38 mitogenactivated protein kinase (MAPK) and induces myogenesis. We found that Cullin 2-interacting protein zinc finger SWIM type containing 8 (ZSWIM8) ubiquitin ligase is induced during C2C12 differentiation and is included in the Cdon complex. These results suggest that ZSWIM8 is a Cdon complex-included myogenic protein that prevents C2C12 differentiation without affecting the stability of Bnip[2], Cdon, and JLP. Cdon interacts with BCL2 adenovirus E1B 19 kDa interacting protein 2 (Bnip-2) and cell division cycle 42 (Cdc42), and the Cdon/JLP/Bnip-2/Cdc[42] complex activates p38α/β MAPK and induces m yogenesis[20]

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Conclusion