A novel isoform of ACE2 is expressed in human nasal and bronchial respiratory epithelia and is upregulated in response to RNA respiratory virus infection

Until now was thought to encode five transcripts and one 805 amino acid protein. Here we identify a novel short isoform of ACE2. Short is expressed in the airway epithelium, the main site of SARS-CoV-2 infection; it is substantially upregulated in response to interferon stimulation and RV infection, but not in response to SARS-CoV-2 infection, and it shows differential regulation in asthma patients. This short isoform lacks SARS-CoV-2 spike glycoprotein high-affinity binding sites and altogether, our data are consistent with a model where short may influence host susceptibility to SARS-CoV-2 infection.