Fig. 1

The SARS-CoV-2 entry and life cycle in human lung cells. The S proteins of SARS-CoV-2 bind to the angiotensin-converting enzyme 2 (ACE2) located on the cellular membrane and enters the target cells through an endosomal pathway (1). Then, viral components such as RNA are uncoated in the cytoplasm (2). In keeping, the genome encodes RNA-dependent RNA polymerase (RdRp) (3), which, in turn, participates to producing full-length (+) RNA and full length (−) RNA copies (4). During replication, genome RNA and RNAs which belong to viral structural components are produced. Then, RNAs are translated into viral components and processed by the endoplasmic reticulum (ER)–Golgi apparatus (GA) (5). Once SARS-CoV-2 structural proteins are formed, nucleocapsids initially are assembled in the cytoplasm, and then they are budding into the lumen of the ER and GA (6). Finally, mature viruses are secreted out of the infected cell via exocytosis (7). EE, early endosome