Importance of cholesterol-rich membrane microdomains in the interaction of the S protein of SARS-coronavirus with the cellular receptor angiotensin-converting enzyme 2.
Cholesterol present in the plasma membrane of target cells has been shown to be important for the infection by SARS-CoV. We show that cholesterol depletion by treatment with methyl-beta-cyclodextrin (m beta CD) affects infection by SARS-CoV to the same extent as infection by vesicular stomatitis virus-based pseudotypes containing the surface glycoprotein S of SARS-CoV (VSV-Delta G-S). Therefore, the role of cholesterol for SARS-CoV infection can be assigned to the S protein and is unaffected by other coronavirus proteins. There have been contradictory reports whether or not angiotensin-converting enzyme 2 (ACE2), the cellular receptor for SARS-CoV, is present in detergent-resistant membrane domains. We found that ACE2 of both Vero E6 and Caco-2 cells co-purifies with marker proteins of detergent-resistant membranes supporting the notion that cholesterol-rich microdomains provide a platform facilitating the efficient interaction of the S protein with the cellular receptor ACE2. To understand the involvement of cholesterol in the initial steps of the viral life cycle, we applied a cell-based binding assay with cells expressing the S protein and cells containing angiotensin-converting enzyme 2 (ACE2). Alternatively, we used a soluble S protein as interaction partner. Depletion of cholesterol from the ACE2-expressing cells reduced the binding of S-expressing cells by 50% whereas the binding of soluble S protein was not affected. This result suggests that optimal infection requires a multivalent interaction between viral attachment protein and cellular receptors.
Glende
Joerg
J
Institut für Virologie, Stiftung Tierärztliche Hochschule Hannover, 30559 Hannover, Germany. joerg.glende@tiho-hannover.de
Schwegmann-Wessels
Christel
C
Al-Falah
Marwan
M
Pfefferle
Susanne
S
Qu
Xiuxia
X
Deng
Hongkui
H
Drosten
Christian
C
Naim
Hassan Y
HY
Herrler
Georg
G
D000085962:Angiotensin-Converting Enzyme 2; D000818:Animals; D018938:Caco-2 Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D002784:Cholesterol / Q000378:metabolism*; D006801:Humans; D008562:Membrane Glycoproteins / Q000378:metabolism*; D021962:Membrane Microdomains / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D045473:Severe acute respiratory syndrome-related coronavirus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D064370:Spike Glycoprotein, Coronavirus; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000378:metabolism*; D053586:Virus Internalization / Q000187:drug effects; D047392:beta-Cyclodextrins / Q000494:pharmacology
D008562:Membrane Glycoproteins; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus; D002784:Cholesterol; D007703:Peptidyl-Dipeptidase A; C000705307:ACE2 protein, human; D000085962:Angiotensin-Converting Enzyme 2