Some mt

1
Some mt cp proteins contain subunits encoded by
organelles genome
2

• 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!

3
Plant mtDNA mtDNA recombines to form new genes,
some poison pollen development to create
cytoplasmic male sterility Pollen don't transmit
mito!
4
CMS A 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 22791792.
doi10.1038/cr.2012.43 Comparative expression
profiling of miRNA during anther development in
genetic male sterile and wild type cotton. (2013)
BMC Plant Biology 1366 Differential Proteomic
Analysis of Anthers between Cytoplasmic Male
Sterile and Maintainer Lines in Capsicum annuum
L.(2013) Int. J. Mol. Sci. 14(11), 22982-22996
doi10.3390/ijms141122982 Transcriptome 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.
5
CMS have major increase in respiration and
mitochondria after meiosis 40 x increase in mt/
cell in tapetum 20x in sporogenous cells Often
arise due to recombination creating weird fusion
encoding defective protein poisons
respiration Not enough energy to make good
pollen
6
CMS RF genes often encode protein which restores
good mRNA eg. by splicing fusion in Hong-Lian cms
rice Or by blocking WA352 expression in Wild
Abortive CMS rice Constant battle mito evolve
way to kill pollen and nucleus evolves way to
overcome it.
7

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

8

• Mitochondria and the immune system
• Mitochondria 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

9

• 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

10

• 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

11

• 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

12

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

13
Mitochondria and cell death Cells die many ways,
but mito are often involved
14
Programmed cell death vs necrosis Necrosis progre
ssive loss of membrane integrity swelling of
cytoplasm, release of cell constituents Often
follows irreversible injury Passive Indiscriminate
PCD Active Orderly process mediated by
intracellular death programs May or may not be
due to an external factor Nuclear
condensation Condensation of PM
15
Types of programmed cell death Apoptosis Autophagy
Pyroptosis Ferroptosis Plant programmed cell
death Necroptosis
16
Apoptosis Occurs as normal part of
development e.g. patterning of hands/feet
17
Apoptosis Occurs as normal part of
development Ordered process that breaks cell into
easily recycled pieces
18
Apoptosis Occurs as normal part of development Is
also triggered by many kinds of damage Especially
to DNA Many cancer cells do not commit apoptosis
19
Apoptosis Occurs as normal part of
development Ordered process that breaks cell into
easily recycled pieces Caspases digest proteins
20
Apoptosis Ordered process that breaks cell into
easily recycled pieces Caspases digest
proteins CAD digests DNA
21
Apoptosis Occurs as normal part of
development Two basic steps commitment and
execution
22
Apoptosis Occurs as normal part of
development Two basic steps commitment and
execution Commitment depends on interplay between
various signals Bax Bcl2 have opposite effects
23
Apoptosis Two basic steps commitment and
execution Commitment depends on interplay between
various signals Bax Bcl2 have opposite
effects 2 main pathways extrinsic intrinsic