John Allen | |
|---|---|
 Professor Allen (July 2018) | |
| Born | 23 June 1950 |
| Alma mater | King's College London |
| Scientific career | |
| Fields | Biochemistry |
John Allen (born 23 June 1950 [1] ) is a British biochemist. He is an honorary professor at the Department of Genetics, Evolution and Environment at the University College London in the United Kingdom. [2]
Allen attended Lliswerry Primary School, Newport and Hartridge High School, Newport, Monmouthshire, Wales. He obtained a BSc from King's College London in 1972 from the School of Biological Sciences. He subsequently obtained a PhD from King's College as well. [3] From 1975-1977, Allen was a Science and Engineering Research Council (SERC) postdoctoral research fellow at the Botany School of the University of Oxford. During his position as postdoctoral research assistant at the Department of Biological Sciences, University of Warwick in the UK (1979-1983), he was also a visiting research associate at the University of Illinois at Urbana–Champaign in the US (1980). [4] In 1983 he took up a lectureship in the Department of Pure and Applied Biology at the University of Leeds. He returned to the US from 1986-1987 as a Nuffield Foundation Science Research Fellow at the Lawrence Berkeley Laboratory at the University of California in Berkeley, California. In 1990 he became Professor of Plant Physiology at the University of Oslo, Norway. He moved in 1992 to Sweden where he became the first professor in Plant Cell Biology at Lund University. He stayed in Lund until 2005 when he became Professor of Biochemistry at Queen Mary University of London. He was honoured with a Royal Society-Wolfson Research Merit Award (2005-2009). In 2015, he became honorary professor at University College London.
Allen is a plant biochemist, in particular relating to regulation of photosynthesis. His work has been cited over 12,000 times. [5] He has given over 300 seminars in 22 countries and 4 continents. 19 of these were plenary or named lectures. [1] Professor Allen's name is linked to the CoRR hypothesis which he formulated in 1993 in the Journal of Theoretical Biology, introducing the term “CoRR" in 2003. [6] Briefly, the CoRR hypothesis states that endosymbiotic organelles such as mitochondria and chloroplasts retain genomes to provide for regulation of gene expression by electron transport and the redox state of the organelle.
In addition, Allen works on mitochondrial ageing in relation to sex. [7] [8]
Allen has been granted the following honours and awards: [1]
A chloroplast is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water in the cells. The ATP and NADPH is then used to make organic molecules from carbon dioxide in a process known as the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in unicellular algae, up to 100 in plants like Arabidopsis and wheat.
Photosynthesis is a biological process used by many cellular organisms to convert light energy into chemical energy, which is stored in organic compounds that can later be metabolized through cellular respiration to fuel the organism's activities. The term usually refers to oxygenic photosynthesis, where oxygen is produced as a byproduct, and some of the chemical energy produced is stored in carbohydrate molecules such as sugars, starch, glycogen and cellulose, which are synthesized from endergonic reaction of carbon dioxide with water. Most plants, algae and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the biological energy necessary for complex life on Earth.
Symbiogenesis is the leading evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms. The theory holds that mitochondria, plastids such as chloroplasts, and possibly other organelles of eukaryotic cells are descended from formerly free-living prokaryotes taken one inside the other in endosymbiosis. Mitochondria appear to be phylogenetically related to Rickettsiales bacteria, while chloroplasts are thought to be related to cyanobacteria.
The plastid is a membrane-bound organelle found in the cells of plants, algae, and some other eukaryotic organisms. They are considered to be intracellular endosymbiotic cyanobacteria. Examples include chloroplasts, chromoplasts, and leucoplasts.
Thylakoids are membrane-bound compartments inside chloroplasts and cyanobacteria. They are the site of the light-dependent reactions of photosynthesis. Thylakoids consist of a thylakoid membrane surrounding a thylakoid lumen. Chloroplast thylakoids frequently form stacks of disks referred to as grana. Grana are connected by intergranal or stromal thylakoids, which join granum stacks together as a single functional compartment.
Photorespiration (also known as the oxidative photosynthetic carbon cycle or C2 cycle) refers to a process in plant metabolism where the enzyme RuBisCO oxygenates RuBP, wasting some of the energy produced by photosynthesis. The desired reaction is the addition of carbon dioxide to RuBP (carboxylation), a key step in the Calvin–Benson cycle, but approximately 25% of reactions by RuBisCO instead add oxygen to RuBP (oxygenation), creating a product that cannot be used within the Calvin–Benson cycle. This process lowers the efficiency of photosynthesis, potentially lowering photosynthetic output by 25% in C3 plants. Photorespiration involves a complex network of enzyme reactions that exchange metabolites between chloroplasts, leaf peroxisomes and mitochondria.
Ferredoxins are iron–sulfur proteins that mediate electron transfer in a range of metabolic reactions. The term "ferredoxin" was coined by D.C. Wharton of the DuPont Co. and applied to the "iron protein" first purified in 1962 by Mortenson, Valentine, and Carnahan from the anaerobic bacterium Clostridium pasteurianum.
Robert Hill FRS, known as Robin Hill, was a British plant biochemist who, in 1939, demonstrated the 'Hill reaction' of photosynthesis, proving that oxygen is evolved during the light requiring steps of photosynthesis. He also made significant contributions to the development of the Z-scheme of oxygenic photosynthesis.
In the field of molecular biology, a two-component regulatory system serves as a basic stimulus-response coupling mechanism to allow organisms to sense and respond to changes in many different environmental conditions. Two-component systems typically consist of a membrane-bound histidine kinase that senses a specific environmental stimulus and a corresponding response regulator that mediates the cellular response, mostly through differential expression of target genes. Although two-component signaling systems are found in all domains of life, they are most common by far in bacteria, particularly in Gram-negative and cyanobacteria; both histidine kinases and response regulators are among the largest gene families in bacteria. They are much less common in archaea and eukaryotes; although they do appear in yeasts, filamentous fungi, and slime molds, and are common in plants, two-component systems have been described as "conspicuously absent" from animals.
The CoRR hypothesis states that the location of genetic information in cytoplasmic organelles permits regulation of its expression by the reduction-oxidation ("redox") state of its gene products.
William Martin is an American botanist and microbiologist, currently Head of the Institut für Molekulare Evolution, Heinrich Heine Universität, Düsseldorf.
Chief Sci
John Albert Raven FRS FRSE is a British botanist, and emeritus professor at University of Dundee and the University of Technology Sydney. His primary research interests lie in the ecophysiology and biochemistry of marine and terrestrial primary producers such as plants and algae.
Picozoa, Picobiliphyta, Picobiliphytes, or Biliphytes are protists of a phylum of marine unicellular heterotrophic eukaryotes with a size of less than about 3 micrometers. They were formerly treated as eukaryotic algae and the smallest member of photosynthetic picoplankton before it was discovered they do not perform photosynthesis. The first species identified therein is Picomonas judraskeda. They probably belong in the Archaeplastida as sister of the Rhodophyta.
The evolution of photosynthesis refers to the origin and subsequent evolution of photosynthesis, the process by which light energy is used to assemble sugars from carbon dioxide and a hydrogen and electron source such as water. The process of photosynthesis was discovered by Jan Ingenhousz, a Dutch-born British physician and scientist, first publishing about it in 1779.
Arthur Robert Grossman is an American biologist whose research ranges across the fields of plant biology, microbiology, marine biology, phytochemistry, and photosynthesis. He has been a staff scientist at Carnegie Institution for Science’s Department of Plant Biology since 1982, and holds a courtesy appointment as professor in the Department of Biology at Stanford. He has mentored more than fifteen PhD students and more than thirty post-doctoral fellows. Grossman was the recipient of the Gilbert Morgan Smith Medal in 2009 and the Darbaker Prize for work on microalgae in 2002. He is co-editor in chief of Journal of Phycology, and has served on the editorial boards of major biological journals including the Annual Review of Genetics, Eukaryotic Cell, Journal of Biological Chemistry, and Molecular Plant among others. He has also served on many committees and panels that evaluate scientific directions for the various granting agencies, universities and government departments. He was elected the co-chair of the Gordon Research Conference on Photosynthesis in 2015, and will be chair again in 2017. He also currently serves as Chief of Genetics at Solazyme Inc. which applies plant biology to create oils.
André Tridon Jagendorf was an American Liberty Hyde Bailey Professor Emeritus in the Section of Plant Biology at Cornell University who is notable for providing direct evidence that chloroplasts synthesize adenosine triphosphate (ATP) using the chemiosmotic mechanism proposed by Peter Mitchell.
Prafullachandra Vishnu Sane is an Indian molecular biologist and plant physiologist, known for his pioneering studies on photosynthesis. He is a former director of National Botanical Research Institute and an elected fellow of the Indian Academy of Sciences, Indian National Science Academy, National Academy of Sciences, India, National Academy of Agricultural Sciences and the Maharashtra Academy of Sciences. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards, in 1981, for his contributions to biological sciences.
Chloroplast Sensor Kinase (CSK) is a protein in chloroplasts and cyanobacteria, bacteria from which chloroplasts evolved by endosymbiosis. It is part of a two-component system. In the plant Arabidopsis thaliana CSK is the product of the gene At1g67840. CSK is known in cyanobacteria as the histidine kinase 2.
Rachel Leech was Professor of Plant Sciences at the University of York, UK. Her research focused on chloroplasts and she was a leader in the field of understanding their development and function. She was also one of the early adopters of Arabidopsis thaliana as a model plant to identify the genes involved in chloroplast division.