Sabeeha Merchant | |
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Born | Sabeeha Sabanali Merchant August 31, 1959 |
Alma mater | University of Wisconsin–Madison (PhD) |
Awards | Gilbert Morgan Smith Medal (2006) Member of the National Academy of Sciences (2012) |
Scientific career | |
Institutions | University of California, Berkeley University of California, Los Angeles |
Thesis | The Chlamydomonas reinhardi chloroplast coupling factor 1 : its purification, properties, and aspects of its synthesis in vivo (1983) |
Website | www |
Sabeeha Sabanali Merchant (born 1959) is a professor of plant biology at the University of California, Berkeley. She studies the photosynthetic metabolism and metalloenzymes In 2010 Merchant led the team that sequenced the Chlamydomonas genome. [1] [2] She was elected a member of the National Academy of Sciences in 2012.
Merchant was born in Mumbai. [3] She was unsure what to specialise in, and took an aptitude test at the age of 12. [3] Merchant scored well in the science and the humanities, but was selected for the sciences as there were not enough girls in the class. [3] Merchant attended the J.B. Petit High School for Girls. [4] At the age of fifteen, Merchant started university at St. Xavier's College, where she was one of five women in a class of 300. [5] She relocated to the United States. She joined the University of Wisconsin–Madison in 1978 and became interested in the chemistry of living cells whilst working under the supervision of Glenn Chambliss. [3] [5] Merchant majored in molecular biology and earned her bachelor's degree in 1979. She joined the Enzyme Institute to work as Henry A. Lardy's secretary, but he encouraged her to apply for graduate programs. She eventually earned her PhD at the University of Wisconsin–Madison in 1983. [6] She worked alongside Bruce Selman on the single-cell alga Chlamydomonas reinhardtii . [7] Chlamydomonas reinhardtii is a model organism as it can build the relevant systems for photosynthesis in the absence of light. During her doctorate Merchant purified chloroplast coupling factor 1, a component of the pathway that uses ATP synthase to synthesize adenosine triphosphate.
After completing her PhD, Merchant joined Lawrence Bogorad at Harvard University. [8] She started working on light-regulated gene expression. [3] Unfortunately, four months into her postdoctoral research fellowship there was a fire in the laboratory. [3] During this time she began to read in the library, investigating role of metals in the regulation of photosynthetic electron transport in Chlamydomonas . [3] She studied how cells detect the levels of copper and developed antibodies. [3]
Merchant was the first to demonstrate that the RNA for Chlamydomonas reinhardtii plastocyanin is produced when copper is available. [3] She used pulse-chase analysis to show that whilst plastocyanin is continuously translated, it becomes degraded in systems without enough copper. [9] Merchant showed that the RNA of cytochrome c6, an iron-based protein, is only present in copper deficient cells. [10] She showed that chlamydomonas also contained cytochrome c6, which could step in during photosynthesis if needed. [3]
In 1987 Merchant moved to the University of California, Los Angeles (UCLA). [3] She works on metal nutrient deficiency, which requires water purification systems to generate water that is free of metal contaminants. [3] In her lab experiments are performed in rigorously cleaned glassware, using hydrochloric acid to remove surface metal ions. [3] Her early work considered signalling that responded to copper, but she has since expanded into iron sensing and the impact of iron deficiencies on photosynthesis. In an effort to understand copper sensing, she studied mutants that did not produce plastocyanin. [11] She discovered that the regulator for plastocyanin and cytochrome c regulation was CRR1 (Copper Response Regulator). She worked with Todd Yeates on the structure and genetics of plastocyanin and cytochrome c, uncovering the crystal structures of both proteins. [12] [13] She was awarded the National Academy of Sciences Gilbert Morgan Smith Medal for her contributions to the assembly of metalloenzymes. [14] In 2007 she led a team that sequenced the Chlamydomonas genome. [15] Her inaugural article was published in PNAS in 2009. [16] She spent 2012 on a sabbatical at the Max Planck Institute of Molecular Plant Physiology. [17] She was appointed director of the Institute for Genomics and Proteomics at UCLA in 2014. [18] She also served on the Life Sciences jury for the Infosys Prize in 2017.
Merchant moved to the University of California, Berkeley in 2018. [19] At Berkeley, she is a Professor of Plant and Microbial Biology. [20] Her lab continue to investigate the metabolism of iron and copper, as well as comparative genomics of algae and bioenergy. [20]
Merchant has served as the editor-in-chief of the Annual Review of Plant Biology since 2005, [21] and was editor-in-chief of The Plant Cell from 2015-2019. [22] She serves on the Board of Directors of Annual Reviews. [23]
Her awards and honors include;
Chlamydomonas is a genus of green algae consisting of about 150 species of unicellular flagellates, found in stagnant water and on damp soil, in freshwater, seawater, and even in snow as "snow algae". Chlamydomonas is used as a model organism for molecular biology, especially studies of flagellar motility and chloroplast dynamics, biogenesis, and genetics. One of the many striking features of Chlamydomonas is that it contains ion channels (channelrhodopsins) that are directly activated by light. Some regulatory systems of Chlamydomonas are more complex than their homologs in Gymnosperms, with evolutionarily related regulatory proteins being larger and containing additional domains.
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.
Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae, and in a single group of land plants, the hornworts. Pyrenoids are associated with the operation of a carbon-concentrating mechanism (CCM). Their main function is to act as centres of carbon dioxide (CO2) fixation, by generating and maintaining a CO2 rich environment around the photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Pyrenoids therefore seem to have a role analogous to that of carboxysomes in cyanobacteria.
Chlamydomonas reinhardtii is a single-cell green alga about 10 micrometres in diameter that swims with two flagella. It has a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and an eyespot apparatus that senses light.
Photosystem I is one of two photosystems in the photosynthetic light reactions of algae, plants, and cyanobacteria. Photosystem I is an integral membrane protein complex that uses light energy to catalyze the transfer of electrons across the thylakoid membrane from plastocyanin to ferredoxin. Ultimately, the electrons that are transferred by Photosystem I are used to produce the moderate-energy hydrogen carrier NADPH. The photon energy absorbed by Photosystem I also produces a proton-motive force that is used to generate ATP. PSI is composed of more than 110 cofactors, significantly more than Photosystem II.
The cytochrome b6f complex (plastoquinol/plastocyanin reductase or plastoquinol/plastocyanin oxidoreductase; EC 7.1.1.6) is an enzyme found in the thylakoid membrane in chloroplasts of plants, cyanobacteria, and green algae, that catalyzes the transfer of electrons from plastoquinol to plastocyanin:
Biohydrogen is H2 that is produced biologically. Interest is high in this technology because H2 is a clean fuel and can be readily produced from certain kinds of biomass, including biological waste. Furthermore some photosynthetic microorganisms are capable to produce H2 directly from water splitting using light as energy source.
Phosphoglycolate phosphatase(EC 3.1.3.18; systematic name 2-phosphoglycolate phosphohydrolase), also commonly referred to as phosphoglycolate hydrolase, 2-phosphoglycolate phosphatase, P-glycolate phosphatase, and phosphoglycollate phosphatase, is an enzyme responsible for catalyzing the conversion of 2-phosphoglycolate into glycolate and phosphate:
Light-dependent reactions are certain photochemical reactions involved in photosynthesis, the main process by which plants acquire energy. There are two light dependent reactions: the first occurs at photosystem II (PSII) and the second occurs at photosystem I (PSI).
The Gilbert Morgan Smith Medal is awarded by the U.S. National Academy of Sciences "in recognition of excellence in published research on marine or freshwater algae." It has been awarded every three years since 1979.
In molecular biology, the Ycf4 protein is involved in the assembly of the photosystem I complex which is part of an energy-harvesting process named photosynthesis. Without Ycf4, photosynthesis would be inefficient affecting plant growth. Ycf4 is located in the thylakoid membrane of the chloroplast. Ycf4 is important for the light dependent reaction of photosynthesis. To date, three thylakoid proteins involved in the stable accumulation of PSI have been identified, these are as follows:
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 been 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 been 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 is Chief of Genetics at Solazyme Inc. which applies plant biology to create oils.
Susanne von Caemmerer is an Australian plant physiologist who is a professor and plant physiologist in the Division of Plant Sciences, Research School of Biology at the Australian National University; and the Deputy Director of the ARC Centre of Excellence for Translational Photosynthesis. She has been a leader in developing and refining biochemical models of photosynthesis.
Prachee Avasthi is a Professor of Anatomy and Cell Biology and Science Communicator at Dartmouth College and a co-founder, chief scientific advisor, and incoming CSO at Arcadia Science in Berkeley, California. She works on upwardly motile Chlamydomonas reinhardtii and is on the Board of Directors of eLife.
Francis-André Wollman is a French biologist born on 5 May 1953. He is a research director at the CNRS and works at the Institut de biologie physico-chimique (IBPC) in Paris. He is a member of the French Academy of sciences.
Maureen Hanson is an American molecular biologist and Liberty Hyde Bailey Professor in the Department of Molecular Biology and Genetics at Cornell University in Ithaca, New York. She is a joint member of the Section of Plant Biology and Director of the Center for Enervating Neuroimmune Disease. Her research concerns gene expression in chloroplasts and mitochondria, photosynthesis, and the molecular basis of the disease Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).
Alice Cheung is an American biochemist who is a professor of molecular biology at the University of Massachusetts Amherst. Her research considers the molecular and cellular biology of polarization. She was elected a Fellow of the American Association for the Advancement of Science in 2020.
Mary Belle Allen was an American botanist, chemist, mycologist, algologist, and plant pathologist, and a pioneer of biochemical microbiology. With Daniel I. Arnon and F. Robert Whatley, she did breakthrough research discovering and demonstrating the role of chloroplasts in photosynthesis. In 1962 she received the Darbaker Prize from the Botanical Society of America for her work on microbial algae. In 1967 she was nominated jointly with Arnon and Whatley for a Nobel Prize.
Jen Sheen is a biologist at Massachusetts General Hospital and Harvard Medical School who is known for her work on plant signaling networks. She is an elected member of the American Association for the Advancement of Science.
Christoph Benning is a German–American plant biologist. He is an MSU Foundation Professor and University Distinguished Professor at Michigan State University. Benning's research into lipid metabolism in plants, algae and photosynthetic bacteria, led him to be named Editor-in-Chief of The Plant Journal in October 2008.