Sadasivan Jibin, Singh Manmeet, Sarma Jayasri DAS
Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246, India.
J Biosci. 2017 Jun;42(2):231-244. doi: 10.1007/s12038-017-9676-7.
Intracellular trafficking and localization studies of spike protein from SARS and OC43 showed that SARS spike protein is localized in the ER or ERGIC compartment and OC43 spike protein is predominantly localized in the lysosome. Differential localization can be explained by signal sequence. The sequence alignment using Clustal W shows that the signal sequence present at the cytoplasmic tail plays an important role in spike protein localization. A unique GYQEL motif is identified at the cytoplasmic terminal of OC43 spike protein which helps in localization in the lysosome, and a novel KLHYT motif is identified in the cytoplasmic tail of SARS spike protein which helps in ER or ERGIC localization. This study sheds some light on the role of cytoplasmic tail of spike protein in cell-to-cell fusion, coronavirus host cell fusion and subsequent pathogenicity.
对SARS和OC43刺突蛋白的细胞内运输和定位研究表明，SARS刺突蛋白定位于内质网或内质网-高尔基体中间室，而OC43刺突蛋白主要定位于溶酶体。定位差异可用信号序列来解释。使用Clustal W进行的序列比对表明，位于细胞质尾部的信号序列在刺突蛋白定位中起重要作用。在OC43刺突蛋白的细胞质末端鉴定出一个独特的GYQEL基序，它有助于在溶酶体中定位，而在SARS刺突蛋白的细胞质尾部鉴定出一个新的KLHYT基序，它有助于在内质网或内质网-高尔基体中间室定位。这项研究揭示了刺突蛋白细胞质尾部在细胞间融合、冠状病毒宿主细胞融合及后续致病性中的作用。
