Samara Reck-Peterson | |
---|---|
Born | 1971 (age 51–52) |
Known for | Studies of the motor protein dynein |
Scientific career | |
Institutions | Harvard Medical School University of California, San Diego Howard Hughes Medical Institute |
Thesis | Functional, Biochemical and Biophysical Characterization of Myo2p, a Class V Myosin of the Yeast Saccharomyces cerevisiae |
Doctoral advisor | Mark Mooseker and Peter Novick |
Other academic advisors | Ronald Vale |
Samara Reck-Peterson is an American cell biologist and biophysicist. She is a Professor of Cellular and Molecular Medicine and Cell and Developmental Biology at the University of California, San Diego and an Investigator of the Howard Hughes Medical Institute. She is known for her contributions to our understanding of how dynein, an exceptionally large motor protein that moves many intracellular cargos, [1] works and is regulated. She developed one of the first systems to produce recombinant dynein [2] and discovered that, unlike other cytoskeletal motors, dynein can take a wide variety of step sizes, forward and back and even sideways. [2] [3] She lives in San Diego, California.
Reck-Peterson was educated at Litchfield High School in Litchfield, Minnesota, where she served as senior class president and graduated as salutatorian in 1989. She was an all-state track and cross-country runner and team captain. [4] She was inducted into the Litchfield High School Hall of Fame in 2017. [4]
Reck-Peterson became interested in molecular motors when she took the Physiology Course at the Marine Biological Laboratory at Woods Hole, Massachusetts. She chose the motor protein myosin as the topic of her Ph.D. work in the laboratories of Mark Mooseker and Peter Novick at Yale University. Her work focused on the class V myosins, which have multiple functions in the cell ranging from mRNA transport to cell polarity and membrane trafficking. [5] She developed a modified in vitro motility assay to show that both Myo2p and Myo4p class V myosins in yeast appear to be non-processive motors in the absence of additional regulation, unlike their vertebrate counterparts. [6]
In 2001, Reck-Peterson moved to UCSF to pursue post-doctoral studies with Ronald Vale. She began to work on dynein, a molecular motor that transports cargoes such as proteins, organelles and messenger RNAs to locations where they are needed in the cell. Dynein uses the energy stored in ATP to move towards the "minus end" of microtubules. Defects in dyneins and their regulatory proteins lead to neurodevelopmental and neurodegenerative diseases, showing the importance of microtubule-based transport in long cells such as neurons. [7] Reck-Peterson used single-molecule techniques to examine the stepping behavior of dynein, finding that isolated dynein can step forwards, backwards and even sideways. [2]
In 2007, Reck-Peterson joined the Department of Cell Biology at Harvard Medical School as an assistant professor. She continued to study the mechanism of dynein-mediated transport. [8] Using DNA origami, she created artificial cargos that could be programmed to load onto multiple types of motors, and used these to create competition, or a "tug of war", between motors. [9] She used an assay for long-distance microtubule-based transport in the long, highly polarized hyphae of Aspergillus nidulans [10] to show that Lis-1 is an initiation factor for dynein-mediated transport, [11] and to show that some cargos of microtubule-based motors hitchhike on others. [12] Mutants in the gene encoding Lis-1 are one cause of lissencephaly, a severe brain disorder. In collaboration with Andres Leschziner, she showed that Lis-1 regulates the interaction between dynein and the microtubule in two different ways, [13] [14] and determined the structural basis for the switch between microtubule binding and microtubule release. [15]
In 2015 Reck-Peterson moved to the University of California, San Diego, [16] and in 2018 she became an Investigator of the Howard Hughes Medical Institute. [17]
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nm and have an inner diameter between 11 and 15 nm. They are formed by the polymerization of a dimer of two globular proteins, alpha and beta tubulin into protofilaments that can then associate laterally to form a hollow tube, the microtubule. The most common form of a microtubule consists of 13 protofilaments in the tubular arrangement.
The cilium, is a membrane-bound organelle found on most types of eukaryotic cell. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projection that extends from the surface of the much larger cell body. Eukaryotic flagella found on sperm cells and many protozoans have a similar structure to motile cilia that enables swimming through liquids; they are longer than cilia and have a different undulating motion.
The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is composed of similar proteins in the various organisms. It is composed of three main components, microfilaments, intermediate filaments and microtubules, and these are all capable of rapid growth or disassembly dependent on the cell's requirements.
Myosins are a superfamily of motor proteins best known for their roles in muscle contraction and in a wide range of other motility processes in eukaryotes. They are ATP-dependent and responsible for actin-based motility.
A kinesin is a protein belonging to a class of motor proteins found in eukaryotic cells. Kinesins move along microtubule (MT) filaments and are powered by the hydrolysis of adenosine triphosphate (ATP). The active movement of kinesins supports several cellular functions including mitosis, meiosis and transport of cellular cargo, such as in axonal transport, and intraflagellar transport. Most kinesins walk towards the plus end of a microtubule, which, in most cells, entails transporting cargo such as protein and membrane components from the center of the cell towards the periphery. This form of transport is known as anterograde transport. In contrast, dyneins are motor proteins that move toward the minus end of a microtubule in retrograde transport.
Dyneins are a family of cytoskeletal motor proteins that move along microtubules in cells. They convert the chemical energy stored in ATP to mechanical work. Dynein transports various cellular cargos, provides forces and displacements important in mitosis, and drives the beat of eukaryotic cilia and flagella. All of these functions rely on dynein's ability to move towards the minus-end of the microtubules, known as retrograde transport; thus, they are called "minus-end directed motors". In contrast, most kinesin motor proteins move toward the microtubules' plus-end, in what is called anterograde transport.
Molecular motors are natural (biological) or artificial molecular machines that are the essential agents of movement in living organisms. In general terms, a motor is a device that consumes energy in one form and converts it into motion or mechanical work; for example, many protein-based molecular motors harness the chemical free energy released by the hydrolysis of ATP in order to perform mechanical work. In terms of energetic efficiency, this type of motor can be superior to currently available man-made motors. One important difference between molecular motors and macroscopic motors is that molecular motors operate in the thermal bath, an environment in which the fluctuations due to thermal noise are significant.
Motor proteins are a class of molecular motors that can move along the cytoplasm of cells. They convert chemical energy into mechanical work by the hydrolysis of ATP. Flagellar rotation, however, is powered by a proton pump.
Molecular biophysics is a rapidly evolving interdisciplinary area of research that combines concepts in physics, chemistry, engineering, mathematics and biology. It seeks to understand biomolecular systems and explain biological function in terms of molecular structure, structural organization, and dynamic behaviour at various levels of complexity. This discipline covers topics such as the measurement of molecular forces, molecular associations, allosteric interactions, Brownian motion, and cable theory. Additional areas of study can be found on Outline of Biophysics. The discipline has required development of specialized equipment and procedures capable of imaging and manipulating minute living structures, as well as novel experimental approaches.
Unconventional myosin-Va is a motor protein in charge of the intracellular transport of vesicles, organelles and protein complexes along the actin filaments. In humans it is coded for by the MYO5A gene.
Dynactin subunit 1 is a protein that in humans is encoded by the DCTN1 gene.
Unconventional myosin-VI, is a protein that in humans is coded for by MYO6. Unconventional myosin-VI is a myosin molecular motor involved in intracellular vesicle and organelle transport.
Dynactin is a 23 subunit protein complex that acts as a co-factor for the microtubule motor cytoplasmic dynein-1. It is built around a short filament of actin related protein-1 (Arp1).
Dynein light chain 1, cytoplasmic is a protein that in humans is encoded by the DYNLL1 gene.
Myosin X, also known as MYO10, is a protein that in humans is encoded by the MYO10 gene.
Unconventional myosin-Ia is a protein that in humans is encoded by the MYO1A gene.
Myosin-Ie (Myo1e) is a protein that in humans is encoded by the MYO1E gene.
Ronald David Vale ForMemRS is an American biochemist and cell biologist. He is a professor at the Department of Cellular and Molecular Pharmacology, University of California, San Francisco. His research is focused on motor proteins, particularly kinesin and dynein. He was awarded the Canada Gairdner International Award for Biomedical Research in 2019, the Shaw Prize in Life Science and Medicine in 2017 together with Ian Gibbons, and the Albert Lasker Award for Basic Medical Research in 2012 alongside Michael Sheetz and James Spudich. He is a fellow of the American Academy of Arts and Sciences and a member of the National Academy of Sciences. He was the president of the American Society for Cell Biology in 2012. He has also been an investigator at the Howard Hughes Medical Institute since 1995. In 2019, Vale was named executive director of the Janelia Research Campus and a vice president of HHMI, his appointment began in early 2020.
Intracellular transport is the movement of vesicles and substances within a cell. Intracellular transport is required for maintaining homeostasis within the cell by responding to physiological signals. Proteins synthesized in the cytosol are distributed to their respective organelles, according to their specific amino acid’s sorting sequence. Eukaryotic cells transport packets of components to particular intracellular locations by attaching them to molecular motors that haul them along microtubules and actin filaments. Since intracellular transport heavily relies on microtubules for movement, the components of the cytoskeleton play a vital role in trafficking vesicles between organelles and the plasma membrane by providing mechanical support. Through this pathway, it is possible to facilitate the movement of essential molecules such as membrane‐bounded vesicles and organelles, mRNA, and chromosomes.
Erika L F. Holzbaur is an American biologist who is the William Maul Measey Professor of Physiology at University of Pennsylvania Perelman School of Medicine. Her research considers the dynamics of organelle motility along cytoskeleton of cells. She is particularly interested in the molecular mechanisms that underpin neurodegenerative diseases.