2003年2月
Localization, topology, and function of the LCB1 subunit of serine palmitolyltransferase in mammalian cells
JOURNAL OF BIOLOGICAL CHEMISTRY
- ,
- ,
- 巻
- 278
- 号
- 6
- 開始ページ
- 4176
- 終了ページ
- 4183
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1074/jbc.M209602200
- 出版者・発行元
- AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
Serine palmitoyltransferase (SPT), the enzyme catalyzing the initial step in the biosynthesis of sphingolipids, comprises two different subunits, LCB1 and LCB2. LCB1 has a single highly hydrophobic domain near the N terminus. Chinese hamster ovary cell mutant LY-B cells are defective in SPT activity because of the lack of expression of an endogenous LCB1 subunit. Stable expression of LCB1 having an epitope tag at either the N or C terminus restored SPT activity of LY-B cells, suggesting that the epitope tag did not affect the localization or topology of LCB1. Indirect immunostaining showed that the N- and C-terminal epitopes are oriented toward the lumenal and cytosol side, respectively, at the endoplasmic reticulum. Interestingly, there was far less LCB2 in LY-B cells than in wild-type cells, and the amount of LCB2 in LY-B cells was restored to the wild-type level by transfection with LCB1 eDNA. In addition, overproduction of the LCB2 subunit required co-overproduction of the LCB1 subunit. These results indicated that the LCB1 subunit is most likely an integral protein having a single transmembrane domain with a lumenal orientation of its N terminus in the endoplasmic reticulum and that the LCB1 subunit is indispensable for the maintenance of the LCB2 subunit in mammalian cells.
- リンク情報
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- DOI
- https://doi.org/10.1074/jbc.M209602200
- CiNii Articles
- http://ci.nii.ac.jp/naid/80015796644
- PubMed
- https://www.ncbi.nlm.nih.gov/pubmed/12464627
- Web of Science
- https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000180869700085&DestApp=WOS_CPL
- ID情報
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- DOI : 10.1074/jbc.M209602200
- ISSN : 0021-9258
- CiNii Articles ID : 80015796644
- PubMed ID : 12464627
- Web of Science ID : WOS:000180869700085