S Protein, ACE2 and Host Cell Proteases in SARS-CoV-2 Cell Entry and Infectivity; Is Soluble ACE2 a Two Blade Sword?...

Area of Science:

• Virology
• Molecular Biology
• Cell Biology

Background:

• The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread globally in late 2019.
• Understanding viral entry mechanisms is crucial for developing effective countermeasures.
• Key interactions involve viral spike proteins and host cell receptors.

Purpose of the Study:

• To review the complex process of SARS-CoV-2 entry into host cells.
• To elucidate the roles of viral and host proteins in this process.
• To examine the impact of soluble angiotensin-converting enzyme II on viral infectivity.

Main Methods:

• Review of existing literature on SARS-CoV-2 cell entry.
• Analysis of the structural and functional roles of spike protein and ACE2.
• Discussion of host proteases and proteins involved in viral invasion.

Main Results:

• Detailed description of sequential conformational changes in the SARS-CoV-2 spike protein facilitating ACE2 binding.
• Identification of host proteases and proteins exploited by the virus for entry.
• Consideration of the release of soluble ACE2 and its dual effect on viral infectivity.

Conclusions:

• The interaction between the viral spike protein and host ACE2 is a critical determinant of SARS-CoV-2 cell entry.
• Host cell machinery, including proteases, is essential for facilitating viral invasion.
• The shedding of ACE2 presents a complex regulatory mechanism influencing viral spread.