Okamura Kosuke, Matsushita Shuhei, Kato Yasuhiko, Watanabe Hajime, Matsui Aiko, Oka Toshihiko, Matsuura Tomoaki
Department of Biotechnology, Division of Advance Science and Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Department of Life Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-Ku, Tokyo 171-8501, Japan.
J Biosci Bioeng. 2019 May;127(5):544-548. doi: 10.1016/j.jbiosc.2018.11.003. Epub 2018 Nov 28.
The human mitochondrion-derived calcium transporter Letm1 was synthesized by reconstituted in vitro transcription-translation (IVTT) in cell-sized liposomes and the dependency of Letm1 on phospholipid composition was investigated. Components for IVTT were encapsulated into cell-sized vesicles together with the DNA encoding Letm1, thereby preparing proteoliposomes. The synthesis of Letm1 and pH-dependent calcium transport activity were confirmed by flow cytometry. Finally, we investigated the effect of phospholipid composition on Letm1 transport activity and found that cardiolipin present in the mitochondrial membrane plays an important role on the transport activity of Letm1.
人类线粒体衍生的钙转运蛋白Letm1通过在细胞大小的脂质体中进行体外转录-翻译重组（IVTT）合成，并研究了Letm1对磷脂组成的依赖性。将IVTT的成分与编码Letm1的DNA一起封装到细胞大小的囊泡中，从而制备蛋白脂质体。通过流式细胞术确认了Letm1的合成和pH依赖性钙转运活性。最后，我们研究了磷脂组成对Letm1转运活性的影响，发现线粒体膜中存在的心磷脂对Letm1的转运活性起着重要作用。
