ABSTRACT
Lysyl oxidase (LOX) and four lysyl oxidase-like proteins, LOXL, LOXL2, LOXL3 and LOXL4, each contain a copper binding site, conserved lysyl and tyrosyl residues that may contribute to quinone co-factor formation, and a cytokine receptor-like domain. Each protein differs mainly in their N-terminal sequence, which may confer individual functions. Processing of the LOX proteins by BMP-1 and possibly other mechanisms may result in multiple functional forms. Splicing, reported for LOXL3, may also generate additional variants with unique functions. Each LOX, with its individual, developmentally regulated tissue and cell-specific expression and localization, results in a complex structural and functional variation for the LOX amine oxidases. The presence of only two LOX-like proteins in Drosophila, each with distinct spatial and temporal expression, allows for the assignment of individual function to one of these amine oxidases. Comparative expression analysis of each LOX protein is presented to help determine their functional significance.
Subject(s)
Amino Acid Oxidoreductases/chemistry , Protein-Lysine 6-Oxidase/chemistry , Amino Acid Oxidoreductases/genetics , Amino Acid Oxidoreductases/physiology , Animals , Drosophila/enzymology , Gene Expression Regulation, Developmental , Mice , Myocardium/enzymology , Protein-Lysine 6-Oxidase/genetics , Protein-Lysine 6-Oxidase/physiologyABSTRACT
We have identified a novel 14-exon human lysyl oxidase-like gene, LOXL4, on chromosome 10q24. The cDNA and derived amino acid sequence of LOXL4 demonstrates a conserved C-terminal region including the characteristic copper-binding site, lysyl and tyrosyl residues and a cytokine receptor-like domain. One of the four N-terminal SRCR domains contains a 13 amino acid insertion encoded by a short exon not present within the closely homologous LOXL2 and LOXL3 genes. The 3.5-kb LOXL4 mRNA is present in pancreas and testis and at lower levels in several other tissues. Fibroblasts, smooth muscle and osteosarcoma (HOS) cells express LOXL4. No expression was detected in HCT-116 and DLD-1 colon, MCF-7 breast and DU-145 prostate cancer cell lines.
Subject(s)
Amino Acid Oxidoreductases/genetics , Chromosomes, Human, Pair 10 , Cysteine/metabolism , Membrane Proteins , Receptors, Lipoprotein , 3' Untranslated Regions , 5' Untranslated Regions , Amino Acid Oxidoreductases/classification , Amino Acid Oxidoreductases/metabolism , Amino Acid Sequence , Animals , Base Sequence , Binding Sites , Cysteine/genetics , DNA, Complementary , Exons , Humans , Male , Mice , Molecular Sequence Data , Open Reading Frames , Protein Structure, Tertiary , Protein-Lysine 6-Oxidase , Receptors, Immunologic/genetics , Receptors, Immunologic/metabolism , Receptors, Scavenger , Scavenger Receptors, Class B , Tissue DistributionABSTRACT
Two known glycosides and a novel trisaccharide fatty acid ester were isolated from the n-butanol-soluble fraction of the fruits of Morinda citrifolia (noni). Structure determination was carried out by spectral techniques such as MS, IR, NMR, and 2D-NMR. The novel trisaccharide fatty acid ester was elucidated as 2, 6-di-O-(beta-D-glucopyranosyl)-1-O-octanoyl-beta-D-glucopyranose. The known compounds were identified as rutin and asperulosidic acid.
