[Key role of Asp16 in proteolysis of influenza A NP protein by caspases in infected cells].
The main nucleocapsid protein NP (molecular weight--56 kD) of human influenza A virus (IAV) was found to be subject to the N-terminal proteolysis in position Asp16 with production of aNP (molecular weight--53 kD) in the infected cells' apoptosis. It was assumed that NP of avian and animal influenza viruses was not subject to proteolysis since it has Gly16. To verify the above assumption the NP chimeric gene of human influenza virus was developed; Asp16 was replaced by Gly by means of "site-oriented" mutagenesis in the above gene, after that, the A/WSN/33 (H1N1) mutant of human influenza virus with "avian" NP and with point mutation (Gly16) was developed by using the method of "reverse genetics". The "human" influenza virus with "avian" chimeric NP/Gly16 turned out to be viable but had a lower replication velocity versus its wild-nature counterpart. It is noteworthy, that the mutant virus caused the cellular apoptosis in the remote infection period the way the wild virus did; however, NP of the former was found to be resistant to cellular caspasas and was not subject to proteolysis in infected cells. The conclusion is that Asp16 in NP molecule of human IAV is involved into the regulation process of virus replication and is the key element in NP proteolysis by cellular caspasas in cells' apoptosis.
Zhirnov
O P
OP
Vorob'eva
I V
IV
Veselovskiĭ
E M
EM
Klenk
N
N
D000818:Animals; D001224:Aspartic Acid / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D020169:Caspases / Q000378:metabolism*; D002460:Cell Line; D017931:DNA Primers; D004285:Dogs; D006868:Hydrolysis; D009980:Influenza A virus / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014758:Viral Core Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D017931:DNA Primers; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D014758:Viral Core Proteins; D001224:Aspartic Acid; D020169:Caspases