Disease relevance of PLP1

• Induction of circulating myelin basic protein and proteolipid protein-specific transforming growth factor-beta1-secreting Th3 T cells by oral administration of myelin in multiple sclerosis patients [1].
• Chronic experimental allergic encephalomyelitis produced by bovine proteolipid apoprotein: immunological studies in rabbits [2].
• The data suggest that lymphocytes specifically sensitized to the proteolipid may be involved in the pathogenesis of the demyelination in chronic EAE [2].
• Delayed hypersensitivity to proteolipid apoprotein was observed in all rabbits prior to the onset of clinical signs [2].
• In both experiments the anti-PLP response was maximal before or immediately after disease onset and tended to decline during disease progression [3].

High impact information on PLP1

• The precursor sequences, which direct the import of the proteolipid into the mitochondrion, are 61 and 68 amino acids long [4].
• Two cDNAs encoding different precursor proteins of the same mature proteolipid subunit of mitochondrial ATP synthase have been cloned from a bovine cDNA library [4].
• Labeling with N,N'-[14C]dicyclohexylcarbodiimide showed the presence of the proteolipid in vacuoles of mutants in which genes encoding subunits of the catalytic sectors were interrupted [5].
• We have cloned and sequenced the gene encoding the DCCD-binding protein (proteolipid) of the H+-ATPase of bovine chromaffin granules [6].
• cDNA sequence encoding the 16-kDa proteolipid of chromaffin granules implies gene duplication in the evolution of H+-ATPases [6].

Biological context of PLP1

• These findings suggest that the proteolipids of the vacuolar H+-ATPases were evolved in parallel with the eubacterial proteolipid, from a common ancestral gene that underwent gene duplication [6].
• Sequence homology with the vacuolar proteolipid and with the proteolipids of eubacterial-type H+-ATPases was detected [6].
• Cysteine-108 is an acylation site in myelin proteolipid protein [7].
• The amino-acid sequence of bovine myelin lipophilin (proteolipid apoprotein, Folch-protein) has been completed [8].
• In this study we present the complete genomic structure of the bovine PLP gene and its assignment to the long arm of the X-chromosome (BTXq2.1) [9].

Anatomical context of PLP1

• These cleavage sites of trypsin support the suggested orientation of PLP in the myelin membrane and thereby extend our knowledge about the molecular arrangement of the components of this membrane [10].
• Structure and molecular arrangement of proteolipid protein of central nervous system myelin [10].
• The proteolipids of bovine mitochondria and Neurospora mitochondria matched better to the COOH-terminal end of the vacuolar proteolipid [6].
• The influence of the myelin proteolipid apoprotein on lipid chain order and dynamics was studied by 2H NMR of membranes reconstituted with specifically deuterated dimyristoyl phosphatidylcholines [11].
• Peripheral leukocyte population staining did not correlate with clinical signs or sensitization to PLP [12].

Associations of PLP1 with chemical compounds

• We propose that PLP is integrated into the lipid bilayer of myelin with the NH2 terminus and three positively charged hydrophilic loops oriented toward the extracytosolic side of the membrane, whereas one strongly negative hydrophilic loop and the positively charged COOH terminus cover the cytosolic side of the lipid bilayer [10].
• To identify the Cys residue(s) involved in the thioester linkage(s), reduced and carboxyamidomethylated proteolipid protein was labeled with [14C]iodoacetamide upon deacylation with neutral hydroxylamine [7].
• Integral membrane proteins significantly decrease the molecular motion in lipid bilayers: a deuteron NMR relaxation study of membranes containing myelin proteolipid apoprotein [11].
• Liposomes reconstituted with the myelin proteolipid apoprotein transport protons, as assayed by quenching of the fluorescence of 9-aminoacridine [13].
• Expression of a proteolipid gene from a high-copy-number plasmid confers trifluoperazine resistance to Saccharomyces cerevisiae [14].

Physical interactions of PLP1

• Its proteins consisted of (1) two basic proteins (16,000 and 18,500 apparent Mr) that reacted with anti-human CNS myelin basic protein antibodies and (2) a major protein (29,000 apparent Mr) that stained with concanavalin A-horseradish peroxidase and bound to anti-rat CNS myelin proteolipid protein (PLP) antibodies [15].

Other interactions of PLP1

• The sequence surrounding the palmitoylation site in the myelin PLP is strikingly similar to that found in rhodopsin [7].
• In isolated rat myelin, DCCD binds specifically to the proteolipid and not to the myelin basic proteins [13].
• Using an in vitro translation system, we show that the E8 polypeptide binds to ductin, the 16-kDa proteolipid that forms transmembrane channels in both gap junctions and vacuolar H+-ATPase [16].
• Invariance in the shapes of the SPR spectra indicates that no major structural transitions occur in the proteolipid membrane due to cytochrome c binding, i.e., the bilayer character of the lipid phase appears to be preserved during these interactions [17].
• The proteolipid protein has been purified in deoxycholate solutions by chromatography on a blue dye-ligand column, which retained all of the basic protein and 2',3'-cyclic nucleotide-3'-phosphodiesterase, and then on Sephacryl S300, which separated proteolipid protein from phospholipid and high-molecular-weight proteins [18].

Analytical, diagnostic and therapeutic context of PLP1

• Identification of the isolated radioactive peptides by amino acid analysis, peptide sequencing and/or fast-atom bombardment-mass spectrometry revealed that Cys108 in the bovine PLP sequence is an acylated site [7].
• Molecular cloning and sequencing of cDNAs encoding the proteolipid subunit of the vacuolar H(+)-ATPase from a higher plant [19].
• Positive delayed hypersensitivity skin test reactions to PLP occurred in all but one of the PLP-sensitized animals [12].
• The presence of a small multigene family of the 16-kDa proteolipid was confirmed by Southern blot analysis showing that several distinct restriction fragments of oat nuclear DNA hybridized with the VATP-P1 cDNA [19].
• Solid-phase immunoassays for quantitation of antibody to bovine white matter proteolipid apoprotein [20].

References