title: Structures and micelle locations of the nonlipidated and lipidated C-terminal membrane anchor of 2',3'-cyclic nucleotide-3'-phosphodiesterase.
abstract: 2,3'-Cyclic nucleotide-3'-phosphodiesterase (CNP) is a myelin-associated protein, an enzyme abundantly present in the central nervous system of mammals and some vertebrates. In vitro, CNP specifically catalyzes the hydrolysis of 2',3'-cyclic nucleotides to produce 2'-nucleotides, but the physiologically relevant in vivo substrate is still unknown. Recently, it was found that CNP is a possible linker protein between microtubules and the plasma membranes. Since CNP is modified post-translationally by an isoprenylation process at its C terminus, the prenylation is hypothesized to be a requisite process, which permanently anchors CNP to the plasma membrane. This study investigates the molecular mechanism of the interaction between CNP and the plasma membrane, proposing a general model to interpret the structural bases of prenylated proteins binding to the membrane. A 13 residue, C-terminal CNP fragment, C13, was demonstrated to be directly responsible for CNP membrane anchoring. C13 and its lipidated derivative (LIPO-C13) were subjected to conformational analysis in membrane mimetic environments, by means of CD and NMR spectroscopies. The orientation of C13 in relation to the membrane was investigated by NMR and EPR spin labeling studies. Our structural investigation shows that the presence of the lipidic tail is essential for the peptide to be folded and correctly positioned on the membrane surface. A general model is proposed in which the post-translational lipidation is an important biomolecular trick to enlarge the hydrophobic surface and to enable the contact of the protein with membrane.
authors: Department of Pharmaceutical Sciences, University of Salerno, I-84084 Fisciano, Italy.
authors: Cinzia
authors: C
authors: Esposito
authors: Mario
authors: M
authors: Scrima
authors: Alfonso
authors: A
authors: Carotenuto
authors: Annamaria
authors: A
authors: Tedeschi
authors: Paolo
authors: P
authors: Rovero
authors: Gerardino
authors: G
authors: D'Errico
authors: Anna Maria
authors: AM
authors: Malfitano
authors: Maurizio
authors: M
authors: Bifulco
authors: Anna Maria
authors: AM
authors: D'Ursi
mesh_terms: D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D003198:Computer Simulation; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008958:Models, Molecular; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D008823:Micelles; D010455:Peptides; D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases