Disease relevance of nlpB

• A gene for a new lipoprotein in the dapA-purC interval of the Escherichia coli chromosome [1].
• Lipoprotein of gram-negative bacteria is essential for growth and division [2].
• The virion consists of a lipoprotein envelope surrounding an icosahedral capsid composed of dimers of a 183-residue protein, 'core antigen' (HBcAg) [3].
• Lipoprotein e(P4) is essential for hemin uptake by Haemophilus influenzae [4].
• Spleen cells from these mice were unresponsive to a series of B-cell mitogens including LPS prepared from Escherichia coli K235 and from E. coli 0111:B4, lipoprotein mitogen from E. coli, and Nocardia water-soluble mitogen (NWSM) [5].

High impact information on nlpB

• This recognition mechanism provides the basis for regulation of protein transport from the TGN to endosomes/lysosomes, which is shared by sortilin and low-density lipoprotein receptor-related protein [6].
• Human serum albumin, high density and low density lipoprotein, and IgG together protect erythrocytes and platelets against attack by even high doses (5-25 micrograms/ml) of ECH [7].
• A complex of structures including the Ig-receptor molecules, the LPS receptor, and the lipoprotein receptor appear involved in the regulation of mitogenic stimulation of B cells to proliferation and differentiation to IgM-secreting cells [8].
• Removal of ester-linked fatty acids from the amino-terminal end of the lipoprotein by alkaline hydrolysis abolishes the mitogenicity of the lipoprotein [8].
• Cholesteryl ester transfer protein (CETP) facilitates exchange of HDL cholesterol for very low density lipoprotein (VLDL) triglyceride, leading to catabolism of HDL [9].

Chemical compound and disease context of nlpB

• A signal peptidase specifically required for the secretion of the lipoprotein of the Escherichia coli outer membrane cleaves off the signal peptide at the bond between a glycine and a cysteine residue [10].
• The same tetrapeptide occurs in the signal sequence of the prolipoprotein of Escherichia coli, and the cysteine residue in the tetrapeptide of prolipoprotein is modified to form glyceride-cysteine which becomes the NH2 terminus of Braun's lipoprotein [11].
• Plasmids were constructed that contain a thermoinducible runaway replicon and either the E. coli tryptophan or lipoprotein promoter and ribosome binding sites, which served as transcriptional and translational initiation sites for the expression of the bGH gene [12].
• Under the same conditions, globomycin does not prevent the attachment of palmitate or glycerol to the E. coli prolipoprotein but inhibits processing of the modified precursor to the mature lipoprotein [13].
• A characteristic signal peptide is present at the amino terminus whose removal is inhibited by the antibiotic, globomycin, suggesting that mature chitobiase is a lipoprotein with a maturation pathway similar to that of the Escherichia coli major outer membrane lipoprotein [14].

Biological context of nlpB

• When this gene, called nlpB, is expressed from a multicopy plasmid in bacteria grown in the presence of [3H]palmitate, a labeled 37-kDa protein is produced [1].
• This lipoprotein is detected in outer membrane vesicles prepared from osmotically lysed spheroplasts and appears to be nonessential, since a strain in which the nlpB gene is disrupted by insertion of a chloramphenicol resistance gene is still able to grow and shows no discernible NlpB phenotype [1].
• An outer membrane protein playing a critical role in Lpp incorporation was identified, and partial amino acid sequences of the protein, named LolB, were identical to those of HemM, which has been suggested to play a role in 5-aminolevulinic acid synthesis in the cytosol [15].
• (d) The nucleotide sequence from position 46 to 168 of the lpp gene was deleted [16].
• However, the 3' end position of the lpp gene of 154 bp was retained, which contains not only translation termination codons in three different reading frames but also the transcription termination signal of the lpp gene [16].

Anatomical context of nlpB

• Three mutants with impaired ability to invade epithelial cells had the Tn5phoA transposon inserted in the yfgL gene encoding the YfgL lipoprotein [17].
• Anti-immunoglobulin antibodies inhibit the mitogenic stimulation of B cells by lipoprotein [8].
• The Escherichia coli major outer membrane lipoprotein (Lpp) is released from the inner membrane into the periplasm as a complex with a carrier protein, LolA (p20), and is then specifically incorporated into the outer membrane [15].
• The recent model of Treponema pallidum molecular architecture proposes that the vast majority of the bacterium's integral membrane proteins are lipoprotein immunogens anchored in the cytoplasmic membrane while the outer membrane contains only a limited number of surface-exposed transmembrane proteins [18].
• Whereas lipoprotein in the wild-type strain is exclusively located in the outer membrane of the cell envelope, the membrane-bound lipoprotein in this mutant is recovered in both the inner and outer membranes of the cell envelope [19].

Associations of nlpB with chemical compounds

• A slightly larger precursor molecule is detected when minicells expressing nlpB are treated with globomycin, a specific inhibitor of lipoprotein signal peptidase [1].
• This cysteine residue was altered to a glycine residue by guided site-specific mutagenesis using a synthetic oligonucleotide and a plasmid carrying an inducible lipoprotein gene [10].
• It was found that all lipoprotein classes bound LPS in direct proportion to their plasma cholesterol concentration [20].
• Amino acid analysis of the purified mutant lipoprotein indicates that the mutant lipoprotein corresponds to the uncleaved prolipoprotein with a single amino acid replacement of glycine with aspartic acid [19].
• Likewise, when [3H]-palmitate-labeled JE5505 cell envelope was incubated with the MM18 cell envelope containing unmodified prolipoprotein in the presence of detergent, [3H]palmitate radioactivity was incorporated into prolipoprotein by ester linkage and into mature lipoprotein by both ester and amide linkages [21].

Analytical, diagnostic and therapeutic context of nlpB

• Eighteen hours after an intraperitoneal injection of endotoxin, the hepatic LDL-receptor expression and the plasma lipoprotein pattern were analyzed [22].
• We believe that the molecular cloning and characterization of N-SMase cDNA will accelerate the process to define its role as a key regulator in apoptosis, lipid and lipoprotein metabolism, and other cell regulatory pathways [23].
• Immunoblotting analysis using the antibody against the 45-kDa protein revealed a 48-kDa precursor of the protein, which accumulated in the cyanobacterial cells treated with globomycin, an antibiotic that specifically inhibits cleavage of the signal peptide of lipoprotein precursors [24].
• Compared to native apoE3 (299 residues), all had reduced affinity for lipoproteins, as assessed by incubation of 125I-labeled proteins with plasma followed by fractionation of lipoprotein classes by gel filtration [25].
• The mRNA that codes for a structural lipoprotein in the outer membrane was purified from the total RNA by three successive electrophoreses on polyacrylamide slab gels, twice at pH 8.3 and once at pH 3.5 in 7 M urea [26].

References