Structural highlights
Disease
MBP_MOUSE Defects in Mbp are a cause of dysmyelinating diseases such as the shiverer (SHI) and myelin deficient (MLD) diseases characterized by decreased myelination in the CNS, tremors, and convulsions of progressively increasing severity leading to early death. The shiverer mice only express isoform 2, the MLD mice have a reduced amount of Mbp.
Function
MBP_MOUSE The classic group of MBP isoforms (isoform 4-isoform 13) are with PLP the most abundant protein components of the myelin membrane in the CNS. They have a role in both its formation and stabilization. The non-classic group of MBP isoforms (isoform 1-isoform 3/Golli-MBPs) may preferentially have a role in the early developing brain long before myelination, maybe as components of transcriptional complexes, and may also be involved in signaling pathways in T-cells and neural cells. Differential splicing events combined to optional post-translational modifications give a wide spectrum of isomers, with each of them potentially having a specialized function.[1]
Publication Abstract from PubMed
The 18.5 kDa myelin basic protein (MBP), the most abundant splice isoform in adult mammalian myelin, is a multifunctional, intrinsically disordered protein involved in the development and compaction of the myelin sheath in the central nervous system. A highly conserved central segment comprises a membrane-anchoring amphipathic alpha-helix followed by a proline-rich segment that represents a ligand for SH3 domain-containing proteins. Here, we have determined using solution nuclear magnetic resonance spectroscopy the structure of a 36-residue peptide fragment of MBP (murine 18.5 kDa residues S72-S107, denoted the alpha2-peptide) comprising these two structural motifs, in association with dodecylphosphocholine (DPC) micelles. The structure was calculated using CS-ROSETTA (version 1.01) because the nuclear Overhauser effect restraints were insufficient for this protein. The experimental studies were complemented by molecular dynamics simulations of a corresponding 24-residue peptide fragment (murine 18.5 kDa residues E80-G103, denoted the MD-peptide), also in association with a DPC micelle in silico. The experimental and theoretical results agreed well with one another, despite the independence of the starting structures and analyses, both showing membrane association via the amphipathic alpha-helix, and a sharp bend in the vicinity of the Pro93 residue (murine 18.5 kDa sequence numbering). Overall, the conformations elucidated here show how the SH3 ligand is presented to the cytoplasm for interaction with SH3 domain-containing proteins such as Fyn and contribute to our understanding of myelin architecture at the molecular level.
Solution Nuclear Magnetic Resonance Structure and Molecular Dynamics Simulations of a Murine 18.5 kDa Myelin Basic Protein Segment (S72-S107) in Association with Dodecylphosphocholine Micelles.,Ahmed MA, De Avila M, Polverini E, Bessonov K, Bamm VV, Harauz G Biochemistry. 2012 Sep 14. PMID:22947219[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Campagnoni AT, Skoff RP. The pathobiology of myelin mutants reveal novel biological functions of the MBP and PLP genes. Brain Pathol. 2001 Jan;11(1):74-91. PMID:11145205 doi:10.1111/j.1750-3639.2001.tb00383.x
- ↑ Ahmed MA, De Avila M, Polverini E, Bessonov K, Bamm VV, Harauz G. Solution Nuclear Magnetic Resonance Structure and Molecular Dynamics Simulations of a Murine 18.5 kDa Myelin Basic Protein Segment (S72-S107) in Association with Dodecylphosphocholine Micelles. Biochemistry. 2012 Sep 14. PMID:22947219 doi:http://dx.doi.org/10.1021/bi300998x
