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Hayashi Y, Nemoto-Sasaki Y, Matsumoto N, Hama K, Tanikawa T, Oka S, Saeki T, Kumasaka T, Koizumi T, Arai S, Wada I, Yokoyama K, Sugiura T, Yamashita A. Complex formation of sphingomyelin synthase 1 with glucosylceramide synthase increases sphingomyelin and decreases glucosylceramide levels. J Biol Chem 2018; 293:17505-17522. [PMID: 30242129 PMCID: PMC6231140 DOI: 10.1074/jbc.ra118.002048] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 08/21/2018] [Indexed: 12/23/2022] Open
Abstract
Sphingolipids, including sphingomyelin (SM) and glucosylceramide (GlcCer), are generated by the addition of a polar head group to ceramide (Cer). Sphingomyelin synthase 1 (SMS1) and glucosylceramide synthase (GCS) are key enzymes that catalyze the conversion of Cer to SM and GlcCer, respectively. GlcCer synthesis has been postulated to occur mainly in cis-Golgi, and SM synthesis is thought to occur in medial/trans-Golgi; however, SMS1 and GCS are known to partially co-localize in cisternae, especially in medial/trans-Golgi. Here, we report that SMS1 and GCS can form a heteromeric complex, in which the N terminus of SMS1 and the C terminus of GCS are in close proximity. Deletion of the N-terminal sterile α-motif of SMS1 reduced the stability of the SMS1-GCS complex, resulting in a significant reduction in SM synthesis in vivo In contrast, chemical-induced heterodimerization augmented SMS1 activity, depending on an increase in the amount and stability of the complex. Fusion of the SMS1 N terminus to the GCS C terminus via linkers of different lengths increased SM synthesis and decreased GlcCer synthesis in vivo These results suggest that formation of the SMS1-GCS heteromeric complex increases SM synthesis and decreases GlcCer synthesis. Importantly, this regulation of relative Cer levels by the SMS1-GCS complex was confirmed by CRISPR/Cas9-mediated knockout of SMS1 or GCS combined with pharmacological inhibition of Cer transport protein in HEK293T cells. Our findings suggest that complex formation between SMS1 and GCS is part of a critical mechanism controlling the metabolic fate of Cer in the Golgi.
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Affiliation(s)
- Yasuhiro Hayashi
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Yoko Nemoto-Sasaki
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Naoki Matsumoto
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Kotaro Hama
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Takashi Tanikawa
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Saori Oka
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Tadaaki Saeki
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Tatsuya Kumasaka
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Takanori Koizumi
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Seisuke Arai
- Department of Cell Science, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima City, Fukushima 960-1295, Japan
| | - Ikuo Wada
- Department of Cell Science, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima City, Fukushima 960-1295, Japan
| | - Kazuaki Yokoyama
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Takayuki Sugiura
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
| | - Atsushi Yamashita
- From the Faculty of Pharma-Science, Teikyo University, Tokyo 173- 8605, Japan and
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