Drosophila lysyl oxidases Dmloxl-1 and Dmloxl-2 are differentially expressed and the active DmLOXL-1 influences gene expression and development.
Mammalian lysyl oxidase (LOX) is essential for the catalysis of lysyl-derived cross-links in fibrillar collagens and elastin in the extracellular matrix and has also been implicated in cell motility, differentiation, and tumor cell invasion. The active LOX has been shown to translocate to the nuclei of smooth muscle cells and regulate chromatin structure and transcription. It is difficult to interpret the role of the LOX protein as it is co-expressed with other members of the LOX amine oxidase family in most mammalian cells. To investigate the function of the LOX proteins, we have characterized the Drosophila lysyl oxidases Dmloxl-1 and Dmloxl-2. We present the gene, domain structure, and expression pattern of Dmloxl-1 and Dmloxl-2 during development. In early development, only Dmloxl-1 was expressed, which allowed functional studies. We have expressed Dmloxl-1 in S2 cells and determined that it is a catalytically active enzyme, inhibited by beta-amino-proprionitrile (BAPN), a specific LOX inhibitor. We localized DmLOXL-1 in the nuclei in embryos and in adult salivary gland cells in the nuclei, cytoplasm, and cell surface, using immunostaining and a DmLOXL-1 antibody. To address the biological function of Dmloxl-1, we raised larvae under BAPN inhibitory conditions and over-expressed Dmloxl-1 in transgenic Drosophila. DmLOXL-1 inhibition resulted in developmental delay and a shift in sex ratio; over-expression in the w(m4) variegating strain increased drosopterin production, demonstrating euchromatinization. Our previous data on the transcriptional down-regulation of seven ribosomal genes and the glue gene under inhibitory conditions and the current results collectively support a nuclear role for Dmloxl-1 in euchromatinization and gene regulation.
Molnar
Janos
J
Cardiovascular Research Center, John A. Burns School of Medicine, University of Hawaii, Honolulu, 96822, USA.
Ujfaludi
Zsuzsanna
Z
Fong
Sheri F T
SF
Bollinger
John A
JA
Waro
Girma
G
Fogelgren
Ben
B
Dooley
David M
DM
Mink
Matyas
M
Csiszar
Katalin
K
D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D000629:Aminopropionitrile / Q000494:pharmacology; D000818:Animals; D030801:Animals, Genetically Modified; D015152:Blotting, Northern; D002384:Catalysis; D002454:Cell Differentiation; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism; D002874:Chromosome Mapping; D003094:Collagen / Q000737:chemistry; D003593:Cytoplasm / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D015536:Down-Regulation; D004331:Drosophila melanogaster; D004549:Elastin / Q000737:chemistry; D022041:Euchromatin / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D016678:Genome; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000166:cytology; D016133:Polymerase Chain Reaction; D017434:Protein Structure, Tertiary; D008249:Protein-Lysine 6-Oxidase / Q000096:biosynthesis* / Q000737:chemistry*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D012463:Saliva / Q000378:metabolism; D012469:Salivary Glands / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D002843:Chromatin; D017931:DNA Primers; D018076:DNA, Complementary; D022041:Euchromatin; D012333:RNA, Messenger; D011994:Recombinant Proteins; D000629:Aminopropionitrile; D003094:Collagen; D004549:Elastin; D008249:Protein-Lysine 6-Oxidase