title: Determinants for phosphodiesterase 6 inhibition by its gamma-subunit.
abstract: The interaction of phosphodiesterase 6 (PDE6) with its inhibitory Pgamma-subunits (Pgamma) is unparalleled among PDE families and is central to vertebrate phototransduction. The C-terminus of Pgamma occludes the active site of PDE6, thereby preventing hydrolysis of cGMP. In this study, we examine the determinants of this critical interaction using structure-based loss-of-function mutagenesis of a chimeric PDE5/PDE6 catalytic domain and gain-of-function mutagenesis of the PDE5 catalytic domain. This analysis revealed the key role of PDE6-specific residues within the catalytic domain M-loop-alpha-helix 15 region and suggested an important contribution of the H-loop-M-loop interface to the PDE6 inhibition by the Pgamma C-terminus. Identification of the determinants for the PDE6-Pgamma interaction offers insights into the evolution of the visual effector enzyme.
authors.affiliation: Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA.
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Zhang
authors.forename: Nikolai O
authors.initials: NO
authors.lastname: Artemyev
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain; D006152:Cyclic GMP / Q000737:chemistry; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D006801:Humans; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D021122:Protein Subunits / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D021122:Protein Subunits; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6; D006152:Cyclic GMP
references.citation: J Biol Chem. 2000 Dec 29;275(52):41258-62
references.pmid: 11024033
references.citation: Biochem J. 1992 Apr 1;283 ( Pt 1):273-9
references.pmid: 1314566
references.citation: Proc Natl Acad Sci U S A. 1996 May 28;93(11):5407-12
references.pmid: 8643588
references.citation: Biochemistry. 2004 May 25;43(20):6091-100
references.pmid: 15147193
references.citation: J Biol Chem. 2004 Mar 26;279(13):13095-101
references.pmid: 14668322
references.citation: Int J Impot Res. 2004 Jun;16 Suppl 1:S28-33
references.pmid: 15224133
references.citation: Eur J Biochem. 2001 Jan;268(1):168-78
references.pmid: 11121118
references.citation: J Biol Chem. 1998 Sep 18;273(38):24485-90
references.pmid: 9733741
references.citation: J Biol Chem. 2001 Jun 15;276(24):21698-703
references.pmid: 11285263
references.citation: Annu Rev Physiol. 2002;64:153-87
references.pmid: 11826267
references.citation: Handb Exp Pharmacol. 2009;(191):367-408
references.pmid: 19089337
references.citation: Vision Res. 2006 Mar;46(6-7):860-8
references.pmid: 16256165
references.citation: Nature. 2006 Feb 23;439(7079):965-8
references.pmid: 16495997
references.citation: Annu Rev Biochem. 2007;76:481-511
references.pmid: 17376027
references.citation: Invest Ophthalmol Vis Sci. 2006 Dec;47(12):5137-52
references.pmid: 17122096
references.citation: J Biol Chem. 2001 Jul 20;276(29):27527-34
references.pmid: 11375400
references.citation: Proc Natl Acad Sci U S A. 2007 Apr 3;104(14):5782-7
references.pmid: 17389385
references.citation: Proc Natl Acad Sci U S A. 2004 Jun 29;101(26):9624-9
references.pmid: 15210993
references.citation: J Biol Chem. 1997 May 2;272(18):11686-9
references.pmid: 9115217
references.citation: J Biol Chem. 2006 Jun 2;281(22):15412-22
references.pmid: 16595671
references.citation: Biochemistry. 2007 Sep 4;46(35):9992-10000
references.pmid: 17685558
references.citation: EMBO J. 2009 Nov 18;28(22):3613-22
references.pmid: 19798052
references.citation: Pflugers Arch. 2007 Aug;454(5):805-19
references.pmid: 17226052
references.citation: Proc Natl Acad Sci U S A. 2009 Oct 27;106(43):18225-30
references.pmid: 19828435
references.citation: J Biol Chem. 2010 Feb 12;285(7):4455-63
references.pmid: 19948718