The balancing act. Redox poise and signalling

The Drummond lectureQueen Mary, University of London

http://plantcell.lu.se/balancing

New Zealand

Dr Muriel Emma Bell (CBE) was awarded the William Gibson Research Scholarship for Medical Women of the British Empire by the Royal Society of Medicine. This enabled her to work for three years with Professor Jack Drummond at University College, London.

Australia

Australian Academy of Science. Victor Martin Trikojus 1902-1985 went to London, where Trik spent some months with Professor Jack Drummond at University College. This gave him the opportunity of extending his contacts with endocrinologists, as well as getting to know one of the great figures in British nutrition.

Wales….

David Hughes, the first Professor and Head of Department of Microbiology at Cardiff (1964-1982) brought back happy memories of the golden past. He also brought the house down with his story of Sir Jack Drummond who coated a haddock with yellow phosphorus to demonstrate to medical students, its "bioluminescence". Trouble was his hands glowed in the darkened lecture theatre more strongly than the fish!

David Lloyd, Biotype. The Newsletter of the School of Pure & Applied Biology, University of Wales Cardiff. Volume 6 Issue 2 April 1996

Acknowledgements

Lund University Plant Cell Biology-Plant Biochemistry http://plantcell.lu.se

Thomas Pfannschmidt (Now University of Jena, Germany)

Dalibor Stys (Now S. Bohemia University, Czech Republic)

Anders Nilsson (Now Bruker Spectroscopy, Lund)

Sylvan Dubé (Now Laval University, Canada)

Paul Davison (Now Sheffield University, U.K.)

H. Louise Race (Now Aylesbury, U.K.)

Jens Forsberg

Jörgen Ström

Boaz Laadan

Carol Allen

Collaborations

Torbjörn Drakenberg, Sture Forsén (Lund Physical Chemistry 2)

Gerhard Link (University of Bochum, Germany)

Light 2

Light 1

The balancing act1.

Transients, enhancement, and redox poise of cyclic electron flow.

Rates and activities of components.

Myers, J. (1971) Annu. Rev.Plant Physiol. 22, 289-312

Hill, R. (1965) Essays Biochem. 1, 121-151

Park, R. B. and Sane, P.V. (1971) Annu. Rev. Plant Physiol.22, 395-430

NADP + H+ +

NADPH

ATPADP + Pi

2H + 1/2O2

+

2e-

P680

PhQ

AQ

B

PQPQH2

H2O

FeSCyt f

e-PC

P700

A0

A1

FeS

4H+

4H+

Cyt b6

Cyt b62e-

e-2H

+ 2H+

4H+

STROMA

LUMEN

FNRFd

Photosynthesis

Blankenship, R. E. (2002) Molecular Mechanisms of Photosynthesis. Blackwell Science, Oxford

Heathcote, P. et el. (2002) Trends Biochem. Sci. 27, 79-87

Forsberg, J. (2002) PhD thesis. Lund University

Pfannschmidt, T. et al. (1999) IUBMB Life 48, 271-276

The balancing act2.

Protein phosphorylation and state transitions. Post-translational

modification of the structure and function of proteins you already

have.

Allen, J. F. (1992) BBA 1098, 275-225 . Adapted from Allen, J.F. et al. (1981) Nature 291, 25-29

Time (s)

12

3

A B

C

D E F G H

Fi

Dubé, S., Davison, P.A. and Allen, J. F. (unpublished)

State 1State 2

P

P

P

P

P

State 1State 2

Allen, J. F. and Forsberg, J. (2001) Trends Plant Sci.6, 317-326

HP

P

H

P

Nilsson, A. et al. (1997) JBC 272, 18350-18357

The balancing act3.

Redox control of gene expression. Changing transcription and the stoichiometry of complexes.

Allen, J. F. (1992) BBA 1098, 275-225

Pfannschmidt, T. et al. (1999) IUBMB Life 48, 271-276

The balancing act4.

Redox signalling and evolution.

Why chloroplasts (and mitochondria…) have genomes

cpDNA-encoded in all sequenced genomes of photosynthetic plastids

cpDNA-encoded in at least one sequenced plastid genome

Cytochrome b6/f Photosystem IPhotosystem II

A

B

Race, H. L., Herrmann, R. G. and Martin, W. (1999) Trends Genet. 15, 364-370

Allen, J. F. (1993) J. Theor. Biol. 165, 609-631

GENE PROTEIN STANDARD REDOX POTENTIAL, Em7 (mV)

SUBSTRATE

Photosystem II

psbA D1 of PS II reaction centre

+1,170 (P+/P)

-800 (P/P*)

Light

psbD D2 of PS II reaction centre

+1,170 (P+/P)

-800 (P/P*)

Light

psbB, psbC CP47 and CP43

of PS II

- Light

Energy coupling

petA Cytochrome f +350 Pmf (pH)

petB Cytochrome b6 -50 Pmf (pH)

atpA,B,E ATP synthase CF1,,

pH, ATP

atpF,H,I ATP synthase CFoI,III,IV

- pH, ATP

Photosystem I

psaA A1 of PS I reaction centre

-1,250 (P/P*)

+500 (P+/P)

Light

psaB A2 of PS I reaction centre

-1,250 (P/P*)

+500 (P+/P)

Light

Respiration; cyclic electron transport

ndhA-F NADH dehydrogenase subunits 1-5

-324 Respiratory substrates?

CO2 fixation

rbcL Rubisco large subunit

- Carbon dioxide

Chloroplast genes and gene products

Allen, J. F. (1993) J. Theor. Biol. 165, 609-631

The balancing act. Redox poise and signalling

• Transients, enhancement, and redox poise of cyclic electron flow.

• Protein phosphorylation and state transitions.

• Redox control of gene expression.

• Redox signalling and evolution.

Quinone pools: Why is redox poise maintained, apparently

by every possible means?

• Efficiency. Example - state transitions in oxygenic photosynthesis.

• Safety - minimizing single electron transfers to oxygen.

The balancing actPostscript.

The Q-cycle, quinone and superoxide anion radicals. The mitochondrial theory of ageing,

and the evolution of sex.

GENE PROTEIN STANDARD REDOX POTENTIAL, Em7 (mV)

SUBSTRATE

Electron transport

nad1-7 Seven subunits of NADH dehydrogenase

-324 Respiratory substrates

cox1-3 Cytochrome c oxidase subunits I, II and III

+815 Oxygen

Energy coupling

atp6 ATP synthase F1 subunit 6

- Proton motive force, ATP

cob Cytochrome b -50 Proton motive force

Allen, J. F. (1993) J. Theor. Biol. 165, 609-631Mitochondrial genes and gene products

QuickTime™ and aVideo decompressor

are needed to see this picture.

Crofts, A.R., et al. (1998) In Proceedings of the IXth. International Symposium on Phototrophic Prokaryotes, Vienna, (Peschek G., ed.)

ALLEN, J F (1996) J. Theor. Biol. 180, 135-140

Thank you for your attention

The balancing act. Redox poise and signalling

The Drummond lectureQueen Mary, University of London

http://plantcell.lu.se/balancing

ALLEN, J F (1996) J. Theor. Biol. 180, 135-140