1E9K
The structure of the RACK1 interaction sites located within the unique N-terminal region of the cAMP-specific phosphodiesterase, PDE4D5.
Summary for 1E9K
| Entry DOI | 10.2210/pdb1e9k/pdb |
| Descriptor | cAMP-specific 3',5'-cyclic phosphodiesterase 4D (1 entity in total) |
| Functional Keywords | hydrolase, camp-specific phosphodiesterase |
| Biological source | Homo sapiens (Human) |
| Total number of polymer chains | 1 |
| Total formula weight | 4430.99 |
| Authors | Bolger, G.B.,Smith, K.J.,McCahill, A.,Hyde, E.I.,Steele, M.R.,Houslay, M.D. (deposition date: 2000-10-20, release date: 2001-10-18, Last modification date: 2024-05-15) |
| Primary citation | Smith, K.J.,Baillie, G.S.,Hyde, E.I.,Li, X.,Houslay, T.M.,McCahill, A.,Dunlop, A.J.,Bolger, G.B.,Klussmann, E.,Adams, D.R.,Houslay, M.D. 1H NMR structural and functional characterisation of a cAMP-specific phosphodiesterase-4D5 (PDE4D5) N-terminal region peptide that disrupts PDE4D5 interaction with the signalling scaffold proteins, beta-arrestin and RACK1. Cell. Signal., 19:2612-2624, 2007 Cited by PubMed Abstract: The unique 88 amino acid N-terminal region of cAMP-specific phosphodiesterase-4D5 (PDE4D5) contains overlapping binding sites conferring interaction with the signaling scaffold proteins, betaarrestin and RACK1. A 38-mer peptide, whose sequence reflected residues 12 through 49 of PDE4D5, encompasses the entire N-terminal RACK1 Interaction Domain (RAID1) together with a portion of the beta-arrestin binding site. (1)H NMR and CD analyses indicate that this region has propensity to form a helical structure. The leucine-rich hydrophobic grouping essential for RACK1 interaction forms a discrete hydrophobic ridge located along a single face of an amphipathic alpha-helix with Arg34 and Asn36, which also play important roles in RACK1 binding. The Asn22/Pro23/Trp24/Asn26 grouping, essential for RACK1 interaction, was located at the N-terminal head of the amphipathic helix that contained the hydrophobic ridge. RAID1 is thus provided by a distinct amphipathic helical structure. We suggest that the binding of PDE4D5 to the WD-repeat protein, RACK1, may occur in a manner akin to the helix-helix interaction shown for G(gamma) binding to the WD-repeat protein, G(beta). A more extensive section of the PDE4D5 N-terminal sequence (Thr11-Ala85) is involved in beta-arrestin binding. Several residues within the RAID1 helix contribute to this interaction however. We show here that these residues form a focused band around the centre of the RAID1 helix, generating a hydrophobic patch (from Leu29, Val30 and Leu33) flanked by polar/charged residues (Asn26, Glu27, Asp28, Arg34). The interaction with beta-arrestin exploits a greater circumference on the RAID1 helix, and involves two residues (Glu27, Asp28) that do not contribute to RACK1 binding. In contrast, the interaction of RACK1 with RAID1 is extended over a greater length of the helix and includes Leu37/Leu38, which do not contribute to beta-arrestin binding. A membrane-permeable, stearoylated Val12-Ser49 38-mer peptide disrupted the interaction of both beta-arrestin and RACK1 with endogenous PDE4D5 in HEKB2 cells, whilst a cognate peptide with a Glu27Ala substitution selectively failed to disrupt PDE4D5/RACK1 interaction. The stearoylated Val12-Ser49 38-mer peptide enhanced the isoprenaline-stimulated PKA phosphorylation of the beta(2)-adrenergic receptors (beta(2)AR) and its activation of ERK, whilst the Glu27Ala peptide was ineffective in both these regards. PubMed: 17900862DOI: 10.1016/j.cellsig.2007.08.015 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
Download full validation report
