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Plant Physiology May 2021Unilateral incompatibility (UI) manifests as pollen rejection in the pistil, typically when self-incompatible (SI) species are pollinated by self-compatible (SC)...
Unilateral incompatibility (UI) manifests as pollen rejection in the pistil, typically when self-incompatible (SI) species are pollinated by self-compatible (SC) relatives. In the Solanaceae, UI occurs when pollen lack resistance to stylar S-RNases, but other, S-RNase-independent mechanisms exist. Pistils of the wild tomato Solanum pennellii LA0716 (SC) lack S-RNase yet reject cultivated tomato (Solanum lycopersicum, SC) pollen. In this cross, UI results from low pollen expression of a farnesyl pyrophosphate synthase gene (FPS2) in S. lycopersicum. Using pollen from fps2-/- loss-of-function mutants in S. pennellii, we identified a pistil factor locus, ui3.1, required for FPS2-based pollen rejection. We mapped ui3.1 to an interval containing 108 genes situated on the IL 3-3 introgression. This region includes a cluster of ornithine decarboxylase (ODC2) genes, with four copies in S. pennellii, versus one in S. lycopersicum. Expression of ODC2 transcript was 1,034-fold higher in S. pennellii than in S. lycopersicum styles. Pistils of odc2-/- knockout mutants in IL 3-3 or S. pennellii fail to reject fps2 pollen and abolish transmission ratio distortion (TRD) associated with FPS2. Pollen of S. lycopersicum express low levels of FPS2 and are compatible on IL 3-3 pistils, but incompatible on IL 12-3 × IL 3-3 hybrids, which express both ODC2 and ui12.1, a locus thought to encode the SI proteins HT-A and HT-B. TRD observed in F2 IL 12-3 × IL 3-3 points to additional ODC2-interacting pollen factors on both chromosomes. Thus, ODC2 genes contribute to S-RNase independent UI and interact genetically with ui12.1 to strengthen pollen rejection.
Topics: Genes, Plant; Ornithine Decarboxylase; Plant Proteins; Pollen; Ribonucleases; Solanum
PubMed: 33576789
DOI: 10.1093/plphys/kiab062 -
The Journal of Biological Chemistry May 2006Ornithine decarboxylase (ODC) initiates the polyamine biosynthetic pathway. The amount of ODC is altered in response to many growth factors, oncogenes, and tumor... (Review)
Review
Ornithine decarboxylase (ODC) initiates the polyamine biosynthetic pathway. The amount of ODC is altered in response to many growth factors, oncogenes, and tumor promoters and to changes in polyamine levels. Susceptibility to tumor development is increased in transgenic mice expressing high levels of ODC and is decreased in mice with reduced ODC due to loss of one ODC allele or elevated expression of antizyme, a protein that stimulates ODC degradation. This review describes key factors that contribute to the regulation of ODC levels, which can occur at the levels of transcription, translation, and protein turnover.
Topics: Alleles; Animals; Gene Expression Regulation, Enzymologic; Humans; Mice; Models, Biological; Ornithine Decarboxylase; Polyamines; Promoter Regions, Genetic; Protein Biosynthesis; RNA, Messenger; Transcription, Genetic
PubMed: 16459331
DOI: 10.1074/jbc.R500031200 -
Biochemical Society Transactions Nov 1994
Review
Topics: Amino Acid Sequence; Animals; Base Sequence; Humans; Kinetics; Mammals; Molecular Sequence Data; Mutagenesis, Site-Directed; Nucleic Acid Conformation; Ornithine Decarboxylase; Point Mutation; RNA, Messenger; Rats; Recombinant Proteins; Repetitive Sequences, Nucleic Acid
PubMed: 7698473
DOI: 10.1042/bst0220846 -
Advances in Enzyme Regulation 1985Ornithine decarboxylase is a key enzyme in polyamine synthesis and growth of mammalian cells. In this chapter I review recent reports on the purification and properties... (Review)
Review
Ornithine decarboxylase is a key enzyme in polyamine synthesis and growth of mammalian cells. In this chapter I review recent reports on the purification and properties of the pure enzyme, and on the localization, synthesis and regulation of the enzyme in the cell. The use of monospecific antibodies, radiolabeled irreversible inhibitors and cDNA clones for studying enzyme localization, turnover and regulation, is briefly described. This first part is meant to serve as a basis for the analysis of ornithine decarboxylase as a target of chemotherapy. A selection of the most potent inhibitors of ornithine decarboxylase is presented and the effects of some of these in cell culture, in animals and in the clinical setting are reviewed.
Topics: Animals; Antineoplastic Agents; Cells, Cultured; Cloning, Molecular; DNA; Drug Resistance; Eflornithine; Humans; Mice; Neoplasms; Ornithine; Ornithine Decarboxylase; Ornithine Decarboxylase Inhibitors; Protein Biosynthesis; Subcellular Fractions
PubMed: 3939094
DOI: 10.1016/0065-2571(85)90072-x -
Drug Metabolism Reviews 1985
Review
Topics: Animals; Carcinogens; Cell Transformation, Neoplastic; Diet; Growth Substances; Homeostasis; Hormones; Humans; Kinetics; Neoplasms; Ornithine Decarboxylase; Ornithine Decarboxylase Inhibitors; Protein Biosynthesis; Protein Kinases; Substrate Specificity; Transcription, Genetic; Vitamin A
PubMed: 3905315
DOI: 10.3109/03602538508991430 -
Journal of Cellular Biochemistry.... 1995l-Ornithine decarboxylase (ODC) is essential for polyamine synthesis and growth in mammalian cells; it provides putrescine that is usually converted into the higher... (Review)
Review
l-Ornithine decarboxylase (ODC) is essential for polyamine synthesis and growth in mammalian cells; it provides putrescine that is usually converted into the higher polyamines, spermidine and spermine. Many highly specific and potent inhibitors of ODC are based on the lead compound alpha-difluoromethylornithine (DFMO), which is an enzyme-activated irreversible inhibitor. DFMO is accepted as a substrate by ODC and is decarboxylated, leading to the formation of a highly reactive species that forms a covalent adduct with either cysteine-360 (90%) or lysine-69 (10%). Both modifications inactivate the enzyme. ODC activity is normally very highly regulated at both transcriptional and post-transcriptional levels according to the growth state of the cell and the intracellular polyamine content. Experimental over-production of ODC can be caused by either transfection with plasmids containing the ODC cDNA with part of the 5'-untranslated region (5'UTR) deleted under the control of a very strong viral promoter, or transfection of plasmids that cause the overproduction of eIF-4E, reported to be a limiting factor in the translation of mRNAs with extensive secondary structures in the 5'UTR. In both cases, unregulated overexpression of ODC transforms NIH 3T3 cells to a neoplastic state. Along with studies showing that many tumor promoters increase ODC activity and that a number of preneoplastic conditions and tumor samples show high levels of ODC, these results suggest that ODC may act as an oncogene in an appropriate background. This provides a rationale for the possible use of ODC inhibitors as chemopreventive agents.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Animals; Anticarcinogenic Agents; Cell Division; Enzyme Inhibitors; Humans; Ornithine Decarboxylase; Ornithine Decarboxylase Inhibitors; Structure-Activity Relationship
PubMed: 8538190
DOI: 10.1002/jcb.240590817 -
Biochemical Society Transactions Nov 1998
Review
Topics: Animals; Ornithine Decarboxylase; Protein Biosynthesis; Protein Processing, Post-Translational
PubMed: 10047785
DOI: 10.1042/bst0260575 -
American Journal of Medical Genetics.... Dec 2018
Topics: Disease Susceptibility; Humans; Ornithine Decarboxylase; Phenotype
PubMed: 30569558
DOI: 10.1002/ajmg.a.13 -
Biochemical and Biophysical Research... Jan 2000Ornithine decarboxylase (ODC) is a key enzyme in polyamine biosynthesis. Turnover of ODC is extremely rapid and highly regulated, and is accelerated when polyamine... (Review)
Review
Ornithine decarboxylase (ODC) is a key enzyme in polyamine biosynthesis. Turnover of ODC is extremely rapid and highly regulated, and is accelerated when polyamine levels increase. Polyamine-stimulated ODC degradation is mediated by association with antizyme (AZ), an ODC inhibitory protein induced by polyamines. ODC, in association with AZ, is degraded by the 26S proteasome in an ATP-dependent, but ubiquitin-independent, manner. The 26S proteasome irreversibly inactivates ODC prior to its degradation. The inactivation, possibly due to unfolding, is coupled to sequestration of ODC within the 26S proteasome. This process requires AZ and ATP, but not proteolytic activity of the 26S proteasome. The carboxyl-terminal region of ODC presumably exposed by interaction with AZ plays a critical role for being trapped by the 26S proteasome. Thus, the degradation pathway of ODC proceeds as a sequence of multiple distinct processes, including recognition, sequestration, unfolding, translocation, and ultimate degradation mediated by the 26S proteasome.
Topics: Animals; Enzyme Inhibitors; Models, Chemical; Ornithine Decarboxylase; Peptide Hydrolases; Proteasome Endopeptidase Complex; Proteins
PubMed: 10623564
DOI: 10.1006/bbrc.1999.1706 -
Cell Biochemistry and Function Jan 1984
Comparative Study Review
Topics: Animals; Bacteria; Fungi; Isoelectric Point; Liver; Male; Mice; Molecular Weight; Ornithine Decarboxylase; Ornithine Decarboxylase Inhibitors; Plants; Prostate; Protein Conformation; Rats; Substrate Specificity
PubMed: 6380791
DOI: 10.1002/cbf.290020102