title: Phosphorylation of human immunodeficiency virus type 1 capsid protein at serine 16, required for peptidyl-prolyl isomerase-dependent uncoating, is mediated by virion-incorporated extracellular signal-regulated kinase 2.
abstract: We reported previously that Pin1 facilitates human immunodeficiency virus type 1 (HIV-1) uncoating by interacting with the capsid core through the phosphorylated Ser(16)-Pro(17) motif. However, the specific kinase responsible for Ser(16) phosphorylation has remained unknown. Here, we showed that virion-associated extracellular signal-regulated kinase 2 (ERK2) phosphorylates Ser(16). The characterization of immature virions produced by exposing chronically HIV-1LAV-1-infected CEM/LAV-1 cells to 10 µM saquinavir indicated that Ser(16) is phosphorylated after the initiation of Pr55(Gag) processing. Furthermore, a mass spectrometry-based in vitro kinase assay demonstrated that ERK2 specifically phosphorylated the Ser(16) residue in the Ser(16)-Pro(17) motif-containing substrate. The treatment of CEM/LAV-1 cells with the ERK2 inhibitor sc-222229 decreased the Ser(16) phosphorylation level inside virions, and virus partially defective in Ser(16) phosphorylation showed impaired reverse transcription and attenuated replication owing to attenuated Pin1-dependent uncoating. Furthermore, the suppression of ERK2 expression by RNA interference in CEM/LAV-1 cells resulted in suppressed ERK2 packaging inside virions and decreased the Ser(16) phosphorylation level inside virions. Interestingly, the ERK2-packaging-defective virus showed impaired reverse transcription and attenuated HIV-1 replication. Taken together, these findings provide insights into the as-yet-obscure processes in Pin1-dependent HIV-1 uncoating.
authors: Department of Pharmaceutical Biochemistry, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan.
authors: Takeo
authors: T
authors: Dochi
authors: Department of Microbiology and Infection Control, Osaka Medical College, Osaka 569-8686, Japan.
authors: Takashi
authors: T
authors: Nakano
authors: Department of Pharmaceutical Biochemistry, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan.
authors: Mutsumi
authors: M
authors: Inoue
authors: Department of Pharmaceutical Biochemistry, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan.
authors: Nobutoki
authors: N
authors: Takamune
authors: Department of Pharmaceutical Biochemistry, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan.
authors: Shozo
authors: S
authors: Shoji
authors: Department of Microbiology and Infection Control, Osaka Medical College, Osaka 569-8686, Japan.
authors: Kouichi
authors: K
authors: Sano
authors: Department of Pharmaceutical Biochemistry, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan.
authors: Shogo
authors: S
authors: Misumi
mesh_terms: D002460:Cell Line; D016655:HIV Core Protein p24 / Q000378:metabolism*; D015497:HIV-1 / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D019696:Peptidylprolyl Isomerase / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D014779:Virus Replication; D057646:Virus Uncoating
chemical_list: D016655:HIV Core Protein p24; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; C000606846:PIN1 protein, human; D019696:Peptidylprolyl Isomerase