A Combination of M50I and V151I Polymorphic Mutations in HIV-1 Subtype B Integrase Results in Defects in Autoprocessing.

Jun Yang,Suranjana Goswami,Weizhong Chang,Muhammad T Rehman,Qian Chen,Brad T Sherman,Catherine A Rehm,Muhammad A Khan,Tomozumi Imamichi,Ming Hao,Robin L Dewar,Helene C Highbarger

doi:10.3390/v13112331

Jun Yang, Suranjana Goswami + Show 10 more

Open Access

https://doi.org/10.3390/v13112331

Copy DOI

Abstract

We have recently reported that a recombinant HIV-1NL4.3 containing Met-to-Ile change at codon 50 of integrase (IN) (IN:M50I) exhibits suppression of the virus release below 0.5% of WT HIV, and the released viral particles are replication-incompetent due to defects in Gag/GagPol processing by inhibition of the initiation of autoprocessing of GagPol polyproteins in the virions and leads to replication-incompetent viruses. The coexisting Ser-to-Asn change at codon 17 of IN or Asn-to-Ser mutation at codon 79 of RNaseH (RH) compensated the defective IN:M50I phenotype, suggesting that both IN and RH regulate an HIV infectability. In the current study, to elucidate a distribution of the three mutations during anti-retroviral therapy among patients, we performed a population analysis using 529 plasma virus RNA sequences obtained through the MiSeq. The result demonstrated that 14 plasma HIVs contained IN:M50I without the compensatory mutations. Comparing the sequences of the 14 viruses with that of the defective virus illustrated that only Val-to-Ile change at codon 151 of IN (IN:V151I) existed in the recombinant virus. This IN:V151I is known as a polymorphic mutation and was derived from HIVNL4.3 backbone. A back-mutation at 151 from Ile-to-Val in the defective virus recovered HIV replication capability, and Western Blotting assay displayed that the back-mutation restored Gag/GagPol processing in viral particles. These results demonstrate that a combination of IN:M50I and IN:V151I mutations, but not IN:M50I alone, produces a defective virus.

Highlights

Nascent human immunodeficiency virus type 1 (HIV-1) particles released from HIV-1infected cells are immature and un-infectious viruses that contain immature Gag and GagPol polyproteins, accessory proteins including Nef precursor, and viral genomic RNAs [1].The Gag and GagPol polyproteins are composed of non-functional precursors of viral structural proteins (matrix protein (MA), capsid protein (CA), nucleocapsid protein (NC)and the viral enzymes: protease (PR), reverse transcriptase (RT), RNase H (RH), and integrase (IN))
Our previous study using a series of recombinant HIV-1NL4.3 mutants demonstrated that virus containing IN:M50I mutation, modified HIVNL4.3 strain (mNL)(IN:M50I), was a defective virus that suppressed the initial cleavage of GagPol polyproteins and viral release (note: the defective recombinant virus was depicted HIV(IN:M50I) in the previous work [16]; to avoid confusion, the mutant is redesignated as mNL(IN:M50I) in the current study); RH:N79S
We recently reported that the presence of IN:M50I in HIV-1 suppresses virus release and inhibits HIV maturation by interrupting the initiation of autoprocessing; subsequently, the virus is impaired in replication, and other mutations, RH:N79S or IN:S17N, restored the viral replication [16]

Summary

Introduction

Nascent human immunodeficiency virus type 1 (HIV-1) particles released from HIV-1infected cells are immature and un-infectious viruses that contain immature Gag and GagPol polyproteins, accessory proteins including Nef precursor, and viral genomic RNAs [1].The Gag and GagPol polyproteins are composed of non-functional precursors of viral structural proteins (matrix protein (MA), capsid protein (CA), nucleocapsid protein (NC)and the viral enzymes: protease (PR), reverse transcriptase (RT), RNase H (RH), and integrase (IN)). Nascent human immunodeficiency virus type 1 (HIV-1) particles released from HIV-1infected cells are immature and un-infectious viruses that contain immature Gag and GagPol polyproteins, accessory proteins including Nef precursor, and viral genomic RNAs [1]. The Gag and GagPol polyproteins are composed of non-functional precursors of viral structural proteins (matrix protein (MA), capsid protein (CA), nucleocapsid protein (NC). Mature PR cleaves the Gag and GagPol polyproteins at 11 cleavage sites and one site on the Nef precursor and cut off each functional protein in the particles [1,2,3]. While the mechanism of these catalytic activities and regulation of the cleavages by the mature. PR are well-described [4], the regulatory mechanism of initiation of the excision of an embedded immature PR in GagPol polyprotein is less investigated.

Objectives

Methods

Results

Conclusion