Proteolipid protein
| Proteolipid protein | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 276 amino acids | |
| Isoforms | 2 | |
| Identifier | ||
| Gene name | PLP1 | |
| External IDs | ||
The proteolipid protein 1 - also known as lipophilin due to its strong hydrophobic properties - is the most common protein in the myelin sheath of nerve cells in relation to mass . It is a transmembrane protein with four transmembrane domains .
As part of the phylogenetic differentiation, it was “preserved” exceptionally well , so that this protein is 100 percent identical in mice and humans.
It has a molar mass of 30,000 Daltons and, as a membrane protein, stabilizes the myelin sheath. The proteolipid protein is characterized by a high proportion of non-polar amino acids . This structural peculiarity and the covalent bond to fatty acids explains its unusually good solubility in organic solvents, which in part corresponds to that of lipids .
Point mutations in the PLP gene can lead to pronounced myelination disorders in both mice and humans. In humans, this manifests itself as Pelizaeus-Merzbacher's disease (PMK), a disease known as shaking pup in dogs . Another possible consequence is spastic spinal paralysis .
Not only mutations or a lack of the PLP gene , but also duplications of the gene lead to a lighter form of this X-linked hereditary disease. Tripling or even quintupling of the gene lead to a rare, pronounced form of PMK.
PLP knockout mouse mutants initially develop inconspicuously and are significantly older than a year, which has shown that PLP is not absolutely necessary for myelin formation, but initially only promotes the stability of the myelin membrane. At the age of over one year, neurodegenerative symptoms such as ataxia and paralysis appear as signs of progressive axonal dysfunction .
swell
- ↑ UniProt P60201
- ↑ NI Wolf, EA Sistermans, M. Cundall, GM Hobson, AP Davis-Williams, R. Palmer, P. Stubbs, S. Davies, M. Endziniene, Y. Wu, WK Chong, S. Malcolm, R. Surtees, JY Garbern, KJ Woodward: Three or more copies of the proteolipid protein gene PLP1 cause severe Pelizaeus-Merzbacher disease. In: Brain: a journal of neurology. Volume 128, Pt 4 April 2005, pp. 743-751, ISSN 1460-2156 . doi : 10.1093 / brain / awh409 . PMID 15689360 .