Fig. 2.

Molecular pathway of SARS-CoV-2 activation in host cells. Mechanism of docking and internalization of SARS-CoV-2 into host cells are facilitated by host cellular proteins. Docking and host cell entry of SARs-CoV-2 occur via virion-associated “spike protein” recognition and binding with the ACE2 receptor (1). Receptor recognition and ACE2 activation are assisted by transmembrane protein TMPRSS2 (2), which leads to endocytosis of virions (3) and early endosome formation (4), and ultimately responsible for the release of viral RNA into the cytoplasm of host cells causing virulence.

ACE2 = angiotensin-converting enzyme-2; SARS-CoV-2 = severe acute respiratory syndrome coronavirus 2; TMPRSS2 = type-II transmembrane serine protease 2.