title: The adenovirus L4-22K protein has distinct functions in the posttranscriptional regulation of gene expression and encapsidation of the viral genome.
abstract: The adenovirus L4-22K protein is multifunctional and critical for different aspects of viral infection. Packaging of the viral genome into an empty capsid absolutely requires the L4-22K protein to bind to packaging sequences in cooperation with other viral proteins. Additionally, the L4-22K protein is important for the temporal switch from the early to late phase of infection by regulating both early and late gene expression. To better understand the molecular mechanisms of these key functions of the L4-22K protein, we focused our studies on the role of conserved pairs of cysteine and histidine residues in the C-terminal region of L4-22K. We found that mutation of the cysteine residues affected the production of infectious progeny virus but did not interfere with the ability of the L4-22K protein to regulate viral gene expression. These results demonstrate that these two functions of L4-22K may be uncoupled. Mutation of the histidine residues resulted in a mutant with a similar phenotype as a virus deficient in the L4-22K protein, where both viral genome packaging and viral gene expression patterns were disrupted. Interestingly, both mutant L4-22K proteins bound to adenovirus packaging sequences, indicating that the paired cysteine and histidine residues do not function as a zinc finger DNA binding motif. Our results reveal that the L4-22K protein controls viral gene expression at the posttranscriptional level and regulates the accumulation of the L4-33K protein, another critical viral regulator, at the level of alternative pre-mRNA splicing.
authors: Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, New York, USA.
authors: Diana
authors: D
authors: Guimet
authors: Patrick
authors: P
authors: Hearing
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000502:physiology*; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D017931:DNA Primers / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D005455:Fluorescent Antibody Technique; D015967:Gene Expression Regulation, Viral / Q000235:genetics*; D016679:Genome, Viral / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017361:Viral Nonstructural Proteins / Q000235:genetics* / Q000378:metabolism*; D010948:Viral Plaque Assay; D019065:Virus Assembly / Q000502:physiology*
chemical_list: D017931:DNA Primers; C571219:L4-22K protein, adenovirus; D017361:Viral Nonstructural Proteins
references: Bioinformatics. 2007 Nov 1;23(21):2947-8
references: 17846036
references: Proc Natl Acad Sci U S A. 1984 Jun;81(12):3655-9
references: 6587381
references: J Virol. 1998 Oct;72(10):7860-70
references: 9733823
references: J Mol Biol. 1992 May 20;225(2):287-98
references: 1593621
references: J Virol. 2005 May;79(9):5676-83
references: 15827182
references: Hum Gene Ther. 2000 Oct 10;11(15):2105-16
references: 11044912
references: Biochemistry. 2010 Nov 16;49(45):9830-8
references: 20925313
references: Int Rev Immunol. 2004 Jan-Apr;23(1-2):75-111
references: 14690856
references: J Virol. 1996 Jul;70(7):4805-10
references: 8676512
references: J Virol. 2012 Oct;86(19):10474-83
references: 22811519
references: Virus Res. 2010 Aug;151(2):220-8
references: 20621673
references: J Virol. 2011 Jun;85(11):5524-31
references: 21450831
references: J Virol. 2010 Jul;84(14):7096-104
references: 20444889
references: J Virol. 2004 Feb;78(4):1782-91
references: 14747543
references: J Virol. 1998 Jan;72(1):225-35
references: 9420219
references: Oncogene. 2005 Nov 21;24(52):7673-85
references: 16299528
references: J Virol. 2011 Aug;85(15):7849-55
references: 21632753
references: Front Biosci. 2008 May 01;13:5006-15
references: 18508565
references: J Virol. 2003 May;77(9):5295-304
references: 12692231
references: Oncogene. 2005 Nov 21;24(52):7686-96
references: 16299529
references: Virology. 1968 Sep;36(1):115-25
references: 5669982
references: Nucleic Acids Res. 2003 Jan 15;31(2):532-50
references: 12527760
references: J Biol Chem. 2006 Dec 1;281(48):36510-7
references: 17028184
references: J Virol. 2000 Mar;74(6):2687-93
references: 10684284
references: J Virol. 2007 Nov;81(22):12450-7
references: 17804492
references: Biochemistry. 2012 Feb 21;51(7):1357-68
references: 22304326
references: J Virol. 1996 Apr;70(4):2296-306
references: 8642656
references: Curr Top Microbiol Immunol. 2003;272:213-49
references: 12747552
references: Curr Protoc Mol Biol. 2004 Sep;Chapter 4:Unit 4.9
references: 18265351
references: J Virol. 2006 Jul;80(14):6973-81
references: 16809303
references: J Virol. 1990 Jun;64(6):2732-42
references: 2335816
references: Cell Biochem Biophys. 2008;50(3):111-31
references: 18253864
references: J Virol. 2009 Apr;83(7):3049-58
references: 19176628
references: J Virol. 2013 Jun;87(12):6739-47
references: 23552425
references: J Cell Biochem. 2005 Sep 1;96(1):25-35
references: 15988756
references: Virology. 1995 Jun 1;209(2):400-8
references: 7778275