Xiaodong Wang | |||||||||||||||||
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王晓东 | |||||||||||||||||
Born | 1963 (age 60–61) | ||||||||||||||||
Nationality | American [2] | ||||||||||||||||
Education | Beijing Normal University (BSc) University of Texas Southwestern Medical Center (PhD) | ||||||||||||||||
Awards | Eli Lilly Award in Biological Chemistry NAS Award in Molecular Biology Shaw Prize in Life Science and Medicine Richard Lounsbery Award King Faisal International Prize in Medicine | ||||||||||||||||
Known for | Research of programmed cell death by apoptosis and necroptosis | ||||||||||||||||
Scientific career | |||||||||||||||||
Fields | Biochemistry | ||||||||||||||||
Institutions | Emory University University of Texas Southwestern Medical Center Howard Hughes Medical Institute National Institute of Biological Sciences, Beijing BeiGene | ||||||||||||||||
Thesis | Studies on the process of mammalian precursor messenger RNA splice site selection (1991) | ||||||||||||||||
Doctoral advisor | Richard A. Padgett | ||||||||||||||||
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Xiaodong Wang (born 1963) is a Chinese-American biochemist best known for his work with apoptosis,one of the ways through which cells kill themselves.
Wang was born in Wuhan,China in 1963,and was raised in Xinxiang,Henan by his grandparents. His family was relatively well-educated. His grandfather was a high school English teacher,his grandmother a primary school teacher,and his great uncle a biology professor. His primary and secondary coincided with the Cultural Revolution,and he only started high school in 1978 at a top high school in Henan. [1] [3]
He entered the Beijing Normal University in 1980, [1] majoring in biology,and completed 4 years later. [4] His undergraduate thesis supervisor,Shaobai Xue,introduced him to cell biology and biochemistry,and prompted him to pursue postgraduate studies in biochemistry. [1]
Through the government-sponsored Chinese-US Biochemistry Examination and Application (CUSBEA) program,the biochemistry counterpart to CUSPEA,Wang went to the University of Texas Southwestern Medical Center in 1985 for his PhD. [1] The CUSBEA program was initiated by the biochemist Ray Wu at Cornell University and lasted from 1982 to 1989. [5] [6] He graduated in 1991. [4]
After obtaining his PhD,Wang moved to the research group of Joseph L. Goldstein and Michael Stuart Brown,also at the University of Texas Southwestern Medical Center (UTSW) as a postdoctoral fellow. He joined the Department of Biochemistry of Emory University in 1995 as an assistant professor,then returned to UTSW a year later as an assistant professor at its Department of Biochemistry. He was promoted to associate professor in 1999. [4] In 2001,Wang was appointed the George L. MacGregor Distinguished Chair in Biomedical Sciences. [7]
Wang became an investigator at the Howard Hughes Medical Institute in 1997. [8]
Since 2003,Wang has been an investigator at the National Institute of Biological Sciences,Beijing (NIBS). In 2010,he ended all his positions in the United States and returned to China to take up the role of director of NIBS. [7]
Wang co-founded two biotechnology companies:Joyant Pharmaceuticals in 2004 and BeiGene in 2010. [9] He currently chairs the Scientific Advisory Board of BeiGene. [10]
Wang chaired the Science Committee of the Future Science Prize in 2017,and currently sits on the committee. [11]
Wang's research on apoptosis began accidentally when he was a postdoctoral fellow at the research group of Joseph L. Goldstein and Michael Stuart Brown at the University of Texas Southwestern Medical Center. Apoptosis is a form of programmed cell death,which is the mechanisms that cells use kill themselves. Brown and Goldstein were at the time studying the transcriptional regulation of the low-density lipoprotein (LDL) receptor in response to cholesterol level. One of the regulatory mechanisms was through the activation of SREBP,a protein that regulates the manufacturing of mRNA from genes coding for proteins that import and synthesize cholesterol. SREBP bound to nuclear envelope and endoplasmic reticulum membranes,and had to be cleaved to be activated. [12]
In 1995,Wang reported a protein in hamsters believed to be the one that cleaved SREBP. However,he also found that the human counterpart of this hamster protein was CPP32,which itself was related to one of the first proteins shown to be involved in initiating apoptosis. [13] The CPP32 protein was officially renamed caspase 3 the following year. [14]
Breakthrough came during Wang's one year at Emory University,when he developed a cell-free, in vitro system that replicated the activation of caspase 3 and the initiation of apoptosis. [3] Using this system,his group characterized the proteins required for starting apoptosis,including cytochrome c, [15] Bcl-2, [16] APAF1, [17] and pro-caspase-9. [18]
In 1997,his group reported the activation steps of apoptosis:Bcl-2 regulates the release of cytochrome c from the mitochondria to the cytosol,then cytochrome c binds to APAF1 and forms a protein complex called the apoptosome. The apoptosome recruits and cleaves procaspase-9 to the active form caspase-9,which in turn cleaves procaspase-3 to the active caspase 3. [18]
Apart from apoptosis,Wang also discovered the necroptosis pathway,which is the programmed form of necrosis and another way that a cell kills itself. He established the role of RIPK3 and the MLKL protein in necroptosis. [19]
Apoptosis is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic,single-celled microorganisms such as yeast. Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing,cell shrinkage,nuclear fragmentation,chromatin condensation,DNA fragmentation,and mRNA decay. The average adult human loses 50 to 70 billion cells each day due to apoptosis. For the average human child between 8 and 14 years old,each day the approximate loss is 20 to 30 billion cells.
The cytochrome complex,or cyt c,is a small hemeprotein found loosely associated with the inner membrane of the mitochondrion where it plays a critical role in cellular respiration. It transfers electrons between Complexes III and IV. Cytochrome c is highly water-soluble,unlike other cytochromes. It is capable of undergoing oxidation and reduction as its iron atom converts between the ferrous and ferric forms,but does not bind oxygen. It also plays a major role in cell apoptosis. In humans,cytochrome c is encoded by the CYCS gene.
Caspases are a family of protease enzymes playing essential roles in programmed cell death. They are named caspases due to their specific cysteine protease activity –a cysteine in its active site nucleophilically attacks and cleaves a target protein only after an aspartic acid residue. As of 2009,there are 12 confirmed caspases in humans and 10 in mice,carrying out a variety of cellular functions.
Michael Stuart Brown ForMemRS NAS AAA&S APS is an American geneticist and Nobel laureate. He was awarded the Nobel Prize in Physiology or Medicine with Joseph L. Goldstein in 1985 for describing the regulation of cholesterol metabolism.
Sterol regulatory element-binding proteins (SREBPs) are transcription factors that bind to the sterol regulatory element DNA sequence TCACNCCAC. Mammalian SREBPs are encoded by the genes SREBF1 and SREBF2. SREBPs belong to the basic-helix-loop-helix leucine zipper class of transcription factors. Unactivated SREBPs are attached to the nuclear envelope and endoplasmic reticulum membranes. In cells with low levels of sterols,SREBPs are cleaved to a water-soluble N-terminal domain that is translocated to the nucleus. These activated SREBPs then bind to specific sterol regulatory element DNA sequences,thus upregulating the synthesis of enzymes involved in sterol biosynthesis. Sterols in turn inhibit the cleavage of SREBPs and therefore synthesis of additional sterols is reduced through a negative feed back loop.
Apoptosis regulator BAX,also known as bcl-2-like protein 4,is a protein that in humans is encoded by the BAX gene. BAX is a member of the Bcl-2 gene family. BCL2 family members form hetero- or homodimers and act as anti- or pro-apoptotic regulators that are involved in a wide variety of cellular activities. This protein forms a heterodimer with BCL2,and functions as an apoptotic activator. This protein is reported to interact with,and increase the opening of,the mitochondrial voltage-dependent anion channel (VDAC),which leads to the loss in membrane potential and the release of cytochrome c. The expression of this gene is regulated by the tumor suppressor P53 and has been shown to be involved in P53-mediated apoptosis.
The Fas receptor,also known as Fas,FasR,apoptosis antigen 1,cluster of differentiation 95 (CD95) or tumor necrosis factor receptor superfamily member 6 (TNFRSF6),is a protein that in humans is encoded by the FAS gene. Fas was first identified using a monoclonal antibody generated by immunizing mice with the FS-7 cell line. Thus,the name Fas is derived from FS-7-associated surface antigen.
The BCL2 associated agonist of cell death (BAD) protein is a pro-apoptotic member of the Bcl-2 gene family which is involved in initiating apoptosis. BAD is a member of the BH3-only family,a subfamily of the Bcl-2 family. It does not contain a C-terminal transmembrane domain for outer mitochondrial membrane and nuclear envelope targeting,unlike most other members of the Bcl-2 family. After activation,it is able to form a heterodimer with anti-apoptotic proteins and prevent them from stopping apoptosis.
Caspase-9 is an enzyme that in humans is encoded by the CASP9 gene. It is an initiator caspase,critical to the apoptotic pathway found in many tissues. Caspase-9 homologs have been identified in all mammals for which they are known to exist,such as Mus musculus and Pan troglodytes.
X-linked inhibitor of apoptosis protein (XIAP),also known as inhibitor of apoptosis protein 3 (IAP3) and baculoviral IAP repeat-containing protein 4 (BIRC4),is a protein that stops apoptotic cell death. In humans,this protein (XIAP) is produced by a gene named XIAP gene located on the X chromosome.
Caspase-3 is a caspase protein that interacts with caspase-8 and caspase-9. It is encoded by the CASP3 gene. CASP3 orthologs have been identified in numerous mammals for which complete genome data are available. Unique orthologs are also present in birds,lizards,lissamphibians,and teleosts.
Caspase-7,apoptosis-related cysteine peptidase,also known as CASP7,is a human protein encoded by the CASP7 gene. CASP7 orthologs have been identified in nearly all mammals for which complete genome data are available. Unique orthologs are also present in birds,lizards,lissamphibians,and teleosts.
Sterol regulatory element-binding protein 2 (SREBP-2) also known as sterol regulatory element binding transcription factor 2 (SREBF2) is a protein that in humans is encoded by the SREBF2 gene.
Caspase-10 is an enzyme that,in humans,is encoded by the CASP10 gene.
Apoptotic protease activating factor 1,also known as APAF1,is a human homolog of C. elegans CED-4 gene.
Caspase-activated DNase (CAD) or DNA fragmentation factor subunit beta is a protein that in humans is encoded by the DFFB gene. It breaks up the DNA during apoptosis and promotes cell differentiation. It is usually an inactive monomer inhibited by ICAD. This is cleaved before dimerization.
Caspase-2 is an enzyme. This enzyme catalyses the following chemical reaction
The Early 35 kDa protein,or P35 in short,is a baculoviral protein that inhibits apoptosis in the cells infected by the virus. Although baculoviruses infect only invertebrates in nature,ectopic expression of P35 in vertebrate animals and cells also results in inhibition of apoptosis,thus indicating a universal mechanism. P35 has been shown to be a caspase inhibitor with a very wide spectrum of activity both in regard to inhibited caspase types and to species in which the mechanism is conserved.
Junying Yuan is the Elizabeth D. Hay Professor of Cell Biology at Harvard Medical School,best known for her work in cell death. Early in her career,she contributed significant findings to the discovery and characterization of apoptosis. More recently,she was responsible for the discovery of the programmed form of necrotic cell death known as necroptosis.
Ced-3 is one of the major protein components of the programmed cell death (PCD) pathway for Caenorhabditis elegans. There are in total 14 genes that are involved in programmed cell death,other important ones including ced-4 and ced-9 genes. The healthy nematode worm will require 131 somatic cell deaths out of the 1090 cells during the developmental stages. The gene initially encodes for a prototypical caspase (procaspase) where the active cysteine residue cleaves aspartate residues,thus becoming a functional caspase. Ced-3 is an executioner caspase that must dimerize with itself and be initiated by ced-4 in order to become active. Once active,it will have a series of reactions that will ultimately lead to the apoptosis of targeted cells.