Some mt & cp proteins contain subunits encoded by organelle’s genome

Some mt & cp proteins contain subunits encoded by organelle’s genome

Plant mtDNA encodes ~13 proteins, also rRNA & tRNA• subunits of ATP synthase & complexes I, II, III & IV• some mRNA are trans-spliced from 2 diff transcripts!• some mRNA are edited: bases changed after synthesis!

Plant mtDNA mtDNA recombines to form new genes, some poison pollen development to create cytoplasmic male sterilityPollen don't transmit mito!

CMSA long noncoding RNA regulates photoperiod-sensitive male sterility, an essential component of hybrid rice(2012) doi: 10.1073/pnas.1121374109 A non-coding RNA locus mediates environment-conditioned male sterility in rice. (2012) Cell Research 22:791–792. doi:10.1038/cr.2012.43Comparative expression profiling of miRNA during anther development in genetic male sterile and wild type cotton. (2013) BMC Plant Biology 13:66Differential Proteomic Analysis of Anthers between Cytoplasmic Male Sterile and Maintainer Lines in Capsicum annuum L.(2013) Int. J. Mol. Sci. 14(11), 22982-22996; doi:10.3390/ijms141122982Transcriptome map of plant mitochondria reveals islands of unexpected transcribed regions (2011) BMC Genomics 12: 279. Heterozygous alleles restore male fertility to cytoplasmic male-sterile radish (Raphanus sativus L.): a case of overdominance(2013) J. Exp. Bot. 64: 2041-2048.

CMShave major increase in respiration and # mitochondria after meiosis40 x increase in mt/ cell in tapetum20x in sporogenous cellsOften arise due to recombinationcreating weird fusion encodingdefective protein: poisons respirationNot enough energy to make good pollen

CMSRF genes often encode protein which restores good mRNA eg. by splicing fusion in Hong-Lian cms riceOr by blocking WA352 expression in Wild Abortive CMS riceConstant battle: mito evolve way to kill pollen and nucleus evolves way to overcome it.

Mitochondria and the immune systemMitochondria are involved in many aspects of innate immunity•Pathogens and damaged mitotrigger very similar responses•pathogen-associated molecular patterns (PAMPs) are bound by pattern-recognition receptors (PRRs)that trigger inflammatory responses•damage-associated molecularpatterns (DAMPs) released by broken mito bind the same receptors & triggersame responses.

Mitochondria and the immune systemMitochondria are involved in many aspects of innate immunity•Mito play important role in recognizing & fighting viruses•Via RLR (retinoic acid-inducible receptors) pathway that detects dsRNA

Mitochondria and the immune system•Mito play important role in recognizing & fighting viruses•Via RLR (retinoic acid-inducible receptors) pathway that detects dsRNA•MAVS (mitochondrial antiviral signaling) protein on MOM is key

Mitochondria and the immune system•Mito play important role in recognizing & fighting viruses•Via RLR (retinoic acid-inducible receptors) pathway that detects dsRNA•MAVS (mitochondrial antiviral signaling) protein on MOM is key•dsRNA receptors bind MAVS &trigger interferon & cytokine synthesis

Mitochondria and the immune system•MAVS (mitochondrial antiviral signaling) protein on MOM is key•dsRNA receptors bind MAVS & trigger interferon & cytokine Synthesis•Viruses also interact with mt in countless specific ways

Mitochondria and the immune system•Viruses also interact with mt in countless specific ways•Many involve blocking Programmed Cell Death pathways

Mitochondria and cell deathCells die many ways, but mito are often involved

Programmed cell death vs necrosisNecrosis:Necrosis:progressive loss of membrane integrity swelling of cytoplasm, release of cell constituents

Often follows irreversible injuryPassiveIndiscriminate

PCDPCD

Active

Orderly process mediated by

intracellular death programs

May or may not be due to an

external factor

Nuclear condensation

Condensation of PM

Types of programmed cell deathApoptosisAutophagyPyroptosisFerroptosisPlant programmed cell deathNecroptosis

ApoptosisOccurs as normal part of developmente.g. patterning of hands/feet

ApoptosisOccurs as normal part of developmentOrdered process that breaks cell into easily recycledpieces

ApoptosisOccurs as normal part of developmentIs also triggered by many kinds of damage

Especially to DNAMany cancer cells do not commit apoptosis

Apoptosis Occurs as normal part of developmentOrdered process that breaks cell into easily recycled pieces Caspases digest proteins

Apoptosis Ordered process that breaks cell into easily recycled pieces Caspases digest proteinsCAD digests DNA

Apoptosis Occurs as normal part of developmentTwo basic steps: commitment and execution

Apoptosis Occurs as normal part of developmentTwo basic steps: commitment and executionCommitment depends on interplay between various signalsBax & Bcl2 have opposite effects

Apoptosis Two basic steps: commitment and executionCommitment depends on interplay between various signalsBax & Bcl2 have opposite effects2 main pathways: extrinsic & intrinsic