1
|
Reekes TH, Higginson CI, Sigvardt KA, King DS, Levine D, Wheelock VL, Disbrow EA. Sex differences in Parkinson disease-associated episodic memory and processing speed deficits. J Int Neuropsychol Soc 2023; 29:813-820. [PMID: 36971238 DOI: 10.1017/s1355617723000097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
OBJECTIVES This study aims to address a gap in the data on cognitive sex differences in persons living with Parkinson disease (PD). There is some evidence that cognitive dysfunction is more severe in male PD, however data on episodic memory and processing speed is incomplete. METHODS One hundred and sixty-seven individuals with a diagnosis of PD were included in this study. Fifty-six of those individuals identified as female. The California Verbal Learning Test 1st edition and the Wechsler Memory Scale 3rd edition were used to evaluate verbal and visuospatial episodic memory and the Wechsler Adult Intelligence Scale 3rd edition was used to evaluate processing speed. Multivariate analysis of covariance was used to identify sex-specific differences across groups. RESULTS Our results show that males with PD performed significantly worse than females in verbal and visuospatial recall as well as a trend for the processing speed task of coding. CONCLUSIONS Our finding of superior performance among females with PD in verbal episodic memory is consistent with reports in both healthy and PD individuals; however, females outperforming males in measures of visuospatial episodic memory is unique to PD. Cognitive deficits preferentially affecting males appear to be associated with frontal lobe-related function. Therefore, males may represent a disease subgroup more susceptible to disease mechanisms affecting frontal lobe deterioration and cognitive disturbances in PD.
Collapse
Affiliation(s)
- Tyler H Reekes
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, USA
- LSU Health Shreveport Center for Brain Health, Shreveport, LA, USA
| | | | - Karen A Sigvardt
- Department of Neurology, University of California Davis, Davis, CA, USA
| | - David S King
- Clinical Functional Neuroscience Department, Kaiser Permanente Northern California, Sacramento, CA, USA
| | - Dawn Levine
- Clinical Functional Neuroscience Department, Kaiser Permanente Northern California, Sacramento, CA, USA
| | - Vicki L Wheelock
- Department of Neurology, University of California Davis, Davis, CA, USA
- Clinical Functional Neuroscience Department, Kaiser Permanente Northern California, Sacramento, CA, USA
| | - Elizabeth A Disbrow
- Department of Pharmacology, Toxicology, and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, USA
- LSU Health Shreveport Center for Brain Health, Shreveport, LA, USA
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| |
Collapse
|
2
|
de Oliveira Mann CC, Orzalli MH, King DS, Kagan JC, Lee ASY, Kranzusch PJ. Modular Architecture of the STING C-Terminal Tail Allows Interferon and NF-κB Signaling Adaptation. Cell Rep 2020; 27:1165-1175.e5. [PMID: 31018131 PMCID: PMC7733315 DOI: 10.1016/j.celrep.2019.03.098] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 02/15/2019] [Accepted: 03/26/2019] [Indexed: 01/28/2023] Open
Abstract
Stimulator of interferon genes (STING) is a key regulator of type I interferon and pro-inflammatory responses during infection, cellular stress, and cancer. Here, we reveal a mechanism for how STING balances activation of IRF3- and NF-κB-dependent transcription and discover that acquisition of discrete signaling modules in the vertebrate STING C-terminal tail (CTT) shapes downstream immunity. As a defining example, we identify a motif appended to the CTT of zebrafish STING that inverts the typical vertebrate signaling response and results in dramatic NF-κB activation and weak IRF3-interferon signaling. We determine a co-crystal structure that explains how this CTT sequence recruits TRAF6 as a new binding partner and demonstrate that the minimal motif is sufficient to reprogram human STING and immune activation in macrophage cells. Together, our results define the STING CTT as a linear signaling hub that can acquire modular motifs to readily adapt downstream immunity. de Oliveira Mann et al. define a mechanism that allows emergence of a signaling response in an innate immune pathway. Modular motifs in the STING CTT control the strength and specificity of downstream responses, and evolutionary acquisition of new signaling elements is facilitated by the linear arrangement of the CTT.
Collapse
Affiliation(s)
- Carina C de Oliveira Mann
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Megan H Orzalli
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - David S King
- HHMI Mass Spectrometry Laboratory, University of California, Berkeley, Berkeley, California 94720, USA
| | - Jonathan C Kagan
- Division of Gastroenterology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Amy S Y Lee
- Department of Biology, Brandeis University, Waltham, MA 02453, USA.
| | - Philip J Kranzusch
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Parker Institute for Cancer Immunotherapy at Dana-Farber Cancer Institute, Boston, MA 02115, USA.
| |
Collapse
|
3
|
Whiteley AT, Eaglesham JB, de Oliveira Mann CC, Morehouse BR, Lowey B, Nieminen EA, Danilchanka O, King DS, Lee ASY, Mekalanos JJ, Kranzusch PJ. Bacterial cGAS-like enzymes synthesize diverse nucleotide signals. Nature 2019; 567:194-199. [PMID: 30787435 PMCID: PMC6544370 DOI: 10.1038/s41586-019-0953-5] [Citation(s) in RCA: 216] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 01/15/2019] [Indexed: 02/07/2023]
Abstract
Cyclic dinucleotides (CDNs) have central roles in bacterial homeostasis and virulence by acting as nucleotide second messengers. Bacterial CDNs also elicit immune responses during infection when they are detected by pattern-recognition receptors in animal cells. Here we perform a systematic biochemical screen for bacterial signalling nucleotides and discover a large family of cGAS/DncV-like nucleotidyltransferases (CD-NTases) that use both purine and pyrimidine nucleotides to synthesize a diverse range of CDNs. A series of crystal structures establish CD-NTases as a structurally conserved family and reveal key contacts in the enzyme active-site lid that direct purine or pyrimidine selection. CD-NTase products are not restricted to CDNs and also include an unexpected class of cyclic trinucleotide compounds. Biochemical and cellular analyses of CD-NTase signalling nucleotides demonstrate that these cyclic di- and trinucleotides activate distinct host receptors and thus may modulate the interaction of both pathogens and commensal microbiota with their animal and plant hosts.
Collapse
Affiliation(s)
- Aaron T Whiteley
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - James B Eaglesham
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Carina C de Oliveira Mann
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Benjamin R Morehouse
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Brianna Lowey
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Eric A Nieminen
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Olga Danilchanka
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Merck Research Laboratories, Merck & Co. Inc., Kenilworth, NJ, USA
| | - David S King
- HHMI Mass Spectrometry Laboratory, University of California, Berkeley, Berkeley, CA, USA
| | - Amy S Y Lee
- Department of Biology, Brandeis University, Waltham, MA, USA
| | - John J Mekalanos
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
| | - Philip J Kranzusch
- Department of Microbiology, Harvard Medical School, Boston, MA, USA. .,Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Parker Institute for Cancer Immunotherapy at Dana-Farber Cancer Institute, Boston, MA, USA.
| |
Collapse
|
4
|
Mann CCDO, King DS, Kranzusch PJ. Abstract B150: STING acquired species-specific motifs to control alternative immune responses. Cancer Immunol Res 2019. [DOI: 10.1158/2326-6074.cricimteatiaacr18-b150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Stimulator of Interferon Genes (STING) is an adaptor protein critical for downstream signaling during recognition of mislocalized cytosolic DNA. STING activation requires recognition of a unique second messenger 2′–5′, 3′–5′ cyclic GMP–AMP (2′3′ cGAMP) synthesized by the pathogen recognition receptor cyclic GMP–AMP synthase (cGAS). Due to its broad expression in most tissues, and ability to respond to different endogenous and foreign small molecules, STING is emerging as a promising drug target for cancer immunotherapy and treatment of autoimmune diseases. However, it remains unknown how the single adaptor protein STING controls distinct transcriptional outputs leading to production of type I interferon, proinflammatory cytokine responses or autophagy. Here we present surprising evidence for the ancient origins of the cGAS-STING signaling pathway by discovery of bacterial cGAS-like enzymes and complete functional cGAS-STING pathways in lower metazoans. Our previous structural data demonstrate that human and metazoan STING proteins share a common architecture that couples ligand binding with conformational changes and allows signal activation. However, it remained unclear how alternative STING conformations control different downstream signaling outputs, and which motifs are responsible for recruitment of the downstream factors controlling each pathway. We have now combined a phylogenetic and biochemical approach to explain the conserved elements that regulate STING downstream signaling events. Our analysis identifies new immune pathway-specific regulatory motifs acquired by distinct STING species, and we are currently focused on identifying the recruited factors important for controlling human STING signaling. Together, our results explain the molecular basis for distinct STING downstream signaling, and provide new insights for the rational design of STING pathway-specific therapeutics.
Citation Format: Carina C. de Oliveira Mann, David S. King, Philip J. Kranzusch. STING acquired species-specific motifs to control alternative immune responses [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B150.
Collapse
Affiliation(s)
| | - David S. King
- Dana-Farber Cancer Institute, Boston, MA; University of California, Berkeley, Berkeley, CA
| | - Philip J. Kranzusch
- Dana-Farber Cancer Institute, Boston, MA; University of California, Berkeley, Berkeley, CA
| |
Collapse
|
5
|
Affiliation(s)
- David S. King
- Department of Psychiatry University of California, Los Angeles
| |
Collapse
|
6
|
Brejc K, Bian Q, Uzawa S, Wheeler BS, Anderson EC, King DS, Kranzusch PJ, Preston CG, Meyer BJ. Dynamic Control of X Chromosome Conformation and Repression by a Histone H4K20 Demethylase. Cell 2017; 171:85-102.e23. [PMID: 28867287 DOI: 10.1016/j.cell.2017.07.041] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/25/2017] [Accepted: 07/25/2017] [Indexed: 02/07/2023]
Abstract
Chromatin modification and higher-order chromosome structure play key roles in gene regulation, but their functional interplay in controlling gene expression is elusive. We have discovered the machinery and mechanism underlying the dynamic enrichment of histone modification H4K20me1 on hermaphrodite X chromosomes during C. elegans dosage compensation and demonstrated H4K20me1's pivotal role in regulating higher-order chromosome structure and X-chromosome-wide gene expression. The structure and the activity of the dosage compensation complex (DCC) subunit DPY-21 define a Jumonji demethylase subfamily that converts H4K20me2 to H4K20me1 in worms and mammals. Selective inactivation of demethylase activity eliminates H4K20me1 enrichment in somatic cells, elevates X-linked gene expression, reduces X chromosome compaction, and disrupts X chromosome conformation by diminishing the formation of topologically associating domains (TADs). Unexpectedly, DPY-21 also associates with autosomes of germ cells in a DCC-independent manner to enrich H4K20me1 and trigger chromosome compaction. Our findings demonstrate the direct link between chromatin modification and higher-order chromosome structure in long-range regulation of gene expression.
Collapse
Affiliation(s)
- Katjuša Brejc
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3204, USA
| | - Qian Bian
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3204, USA
| | - Satoru Uzawa
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3204, USA
| | - Bayly S Wheeler
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3204, USA
| | - Erika C Anderson
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3204, USA
| | - David S King
- HHMI Mass Spectrometry Laboratory, University of California, Berkeley, Berkeley, California 94720-3204, USA
| | - Philip J Kranzusch
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3204, USA
| | - Christine G Preston
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3204, USA
| | - Barbara J Meyer
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3204, USA.
| |
Collapse
|
7
|
Loftus KM, Cui H, Coutavas E, King DS, Ceravolo A, Pereiras D, Solmaz SR. Mechanism for G2 phase-specific nuclear export of the kinetochore protein CENP-F. Cell Cycle 2017; 16:1414-1429. [PMID: 28723232 DOI: 10.1080/15384101.2017.1338218] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Centromere protein F (CENP-F) is a component of the kinetochore and a regulator of cell cycle progression. CENP-F recruits the dynein transport machinery and orchestrates several cell cycle-specific transport events, including transport of the nucleus, mitochondria and chromosomes. A key regulatory step for several of these functions is likely the G2 phase-specific export of CENP-F from the nucleus to the cytosol, where the cytoplasmic dynein transport machinery resides; however, the molecular mechanism of this process is elusive. Here, we have identified 3 phosphorylation sites within the bipartite classical nuclear localization signal (cNLS) of CENP-F. These sites are specific for cyclin-dependent kinase 1 (Cdk1), which is active in G2 phase. Phosphomimetic mutations of these residues strongly diminish the interaction of the CENP-F cNLS with its nuclear transport receptor karyopherin α. These mutations also diminish nuclear localization of the CENP-F cNLS in cells. Notably, the cNLS is phosphorylated in the -1 position, which is important to orient the adjacent major motif for binding into its pocket on karyopherin α. We propose that localization of CENP-F is regulated by a cNLS, and a nuclear export pathway, resulting in nuclear localization during most of interphase. In G2 phase, the cNLS is weakened by phosphorylation through Cdk1, likely resulting in nuclear export of CENP-F via the still active nuclear export pathway. Once CENP-F resides in the cytosol, it can engage in pathways that are important for cell cycle progression, kinetochore assembly and the faithful segregation of chromosomes into daughter cells.
Collapse
Affiliation(s)
- Kyle M Loftus
- a Department of Chemistry , State University of New York at Binghamton , New York , NY , USA
| | - Heying Cui
- a Department of Chemistry , State University of New York at Binghamton , New York , NY , USA
| | - Elias Coutavas
- b Laboratory of Cell Biology , The Rockefeller University , New York , NY , USA
| | - David S King
- c Howard Hughes Medical Institute, Mass Spectrometry Laboratory , University of California at Berkeley , Berkeley , CA , USA
| | - Amanda Ceravolo
- a Department of Chemistry , State University of New York at Binghamton , New York , NY , USA
| | - Dylan Pereiras
- a Department of Chemistry , State University of New York at Binghamton , New York , NY , USA
| | - Sozanne R Solmaz
- a Department of Chemistry , State University of New York at Binghamton , New York , NY , USA
| |
Collapse
|
8
|
Kim AR, Ulirsch JC, Wilmes S, Unal E, Moraga I, Karakukcu M, Yuan D, Kazerounian S, Abdulhay NJ, King DS, Gupta N, Gabriel SB, Lander ES, Patiroglu T, Ozcan A, Ozdemir MA, Garcia KC, Piehler J, Gazda HT, Klein DE, Sankaran VG. Functional Selectivity in Cytokine Signaling Revealed Through a Pathogenic EPO Mutation. Cell 2017. [PMID: 28283061 DOI: 10.1016/j.cell.2017.02.026.functional] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cytokines are classically thought to stimulate downstream signaling pathways through monotonic activation of receptors. We describe a severe anemia resulting from a homozygous mutation (R150Q) in the cytokine erythropoietin (EPO). Surprisingly, the EPO R150Q mutant shows only a mild reduction in affinity for its receptor but has altered binding kinetics. The EPO mutant is less effective at stimulating erythroid cell proliferation and differentiation, even at maximally potent concentrations. While the EPO mutant can stimulate effectors such as STAT5 to a similar extent as the wild-type ligand, there is reduced JAK2-mediated phosphorylation of select downstream targets. This impairment in downstream signaling mechanistically arises from altered receptor dimerization dynamics due to extracellular binding changes. These results demonstrate how variation in a single cytokine can lead to biased downstream signaling and can thereby cause human disease. Moreover, we have defined a distinct treatable form of anemia through mutation identification and functional studies.
Collapse
Affiliation(s)
- Ah Ram Kim
- Division of Hematology/Oncology, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jacob C Ulirsch
- Division of Hematology/Oncology, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Stephan Wilmes
- Department of Biology, Division of Biophysics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Ekrem Unal
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Faculty of Medicine, Erciyes University, Kayseri 38039, Turkey
| | - Ignacio Moraga
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Musa Karakukcu
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Faculty of Medicine, Erciyes University, Kayseri 38039, Turkey
| | - Daniel Yuan
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Shideh Kazerounian
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Nour J Abdulhay
- Division of Hematology/Oncology, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - David S King
- Howard Hughes Medical Institute Mass Spectrometry Laboratory, University of California Berkeley, Berkeley, CA 94720, USA
| | - Namrata Gupta
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Eric S Lander
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Turkan Patiroglu
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Faculty of Medicine, Erciyes University, Kayseri 38039, Turkey
| | - Alper Ozcan
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Faculty of Medicine, Erciyes University, Kayseri 38039, Turkey
| | - Mehmet Akif Ozdemir
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Faculty of Medicine, Erciyes University, Kayseri 38039, Turkey
| | - K Christopher Garcia
- Department of Molecular and Cellular Physiology, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jacob Piehler
- Department of Biology, Division of Biophysics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Hanna T Gazda
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Daryl E Klein
- Department of Pharmacology, Cancer Biology Institute, Yale University School of Medicine, West Haven, CT 06516, USA.
| | - Vijay G Sankaran
- Division of Hematology/Oncology, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| |
Collapse
|
9
|
Su X, Ditlev JA, Hui E, Xing W, Banjade S, Okrut J, King DS, Taunton J, Rosen MK, Vale RD. Phase separation of signaling molecules promotes T cell receptor signal transduction. Science 2016; 352:595-9. [PMID: 27056844 DOI: 10.1126/science.aad9964] [Citation(s) in RCA: 742] [Impact Index Per Article: 92.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 03/23/2016] [Indexed: 12/24/2022]
Abstract
Activation of various cell surface receptors triggers the reorganization of downstream signaling molecules into micrometer- or submicrometer-sized clusters. However, the functional consequences of such clustering have been unclear. We biochemically reconstituted a 12-component signaling pathway on model membranes, beginning with T cell receptor (TCR) activation and ending with actin assembly. When TCR phosphorylation was triggered, downstream signaling proteins spontaneously separated into liquid-like clusters that promoted signaling outputs both in vitro and in human Jurkat T cells. Reconstituted clusters were enriched in kinases but excluded phosphatases and enhanced actin filament assembly by recruiting and organizing actin regulators. These results demonstrate that protein phase separation can create a distinct physical and biochemical compartment that facilitates signaling.
Collapse
Affiliation(s)
- Xiaolei Su
- Howard Hughes Medical Institute (HHMI) Summer Institute, Marine Biological Laboratory, Woods Hole, MA 02543, USA. Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA
| | - Jonathon A Ditlev
- Howard Hughes Medical Institute (HHMI) Summer Institute, Marine Biological Laboratory, Woods Hole, MA 02543, USA. Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Enfu Hui
- Howard Hughes Medical Institute (HHMI) Summer Institute, Marine Biological Laboratory, Woods Hole, MA 02543, USA. Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA
| | - Wenmin Xing
- Howard Hughes Medical Institute (HHMI) Summer Institute, Marine Biological Laboratory, Woods Hole, MA 02543, USA. Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sudeep Banjade
- Howard Hughes Medical Institute (HHMI) Summer Institute, Marine Biological Laboratory, Woods Hole, MA 02543, USA. Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Julia Okrut
- Howard Hughes Medical Institute (HHMI) Summer Institute, Marine Biological Laboratory, Woods Hole, MA 02543, USA. Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA
| | - David S King
- HHMI Mass Spectrometry Laboratory and Department of Molecular and Cellular Biology, University of California, Berkeley, CA 94720, USA
| | - Jack Taunton
- Howard Hughes Medical Institute (HHMI) Summer Institute, Marine Biological Laboratory, Woods Hole, MA 02543, USA. Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA
| | - Michael K Rosen
- Howard Hughes Medical Institute (HHMI) Summer Institute, Marine Biological Laboratory, Woods Hole, MA 02543, USA. Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Ronald D Vale
- Howard Hughes Medical Institute (HHMI) Summer Institute, Marine Biological Laboratory, Woods Hole, MA 02543, USA. Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA.
| |
Collapse
|
10
|
King DS, Baskerville R, Hellsten Y, Senchina DS, Burke LM, Stear SJ, Castell LM. A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance-Part 34. Br J Sports Med 2012; 46:689-90. [PMID: 22711798 DOI: 10.1136/bjsports-2012-091314] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- D S King
- Department of Kinesiology, Iowa State University, Ames, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
Gee CL, Papavinasasundaram KG, Blair SR, Baer CE, Falick AM, King DS, Griffin JE, Venghatakrishnan H, Zukauskas A, Wei JR, Dhiman RK, Crick DC, Rubin EJ, Sassetti CM, Alber T. A phosphorylated pseudokinase complex controls cell wall synthesis in mycobacteria. Sci Signal 2012; 5:ra7. [PMID: 22275220 DOI: 10.1126/scisignal.2002525] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Prokaryotic cell wall biosynthesis is coordinated with cell growth and division, but the mechanisms regulating this dynamic process remain obscure. Here, we describe a phosphorylation-dependent regulatory complex that controls peptidoglycan (PG) biosynthesis in Mycobacterium tuberculosis. We found that PknB, a PG-responsive Ser-Thr protein kinase (STPK), initiates complex assembly by phosphorylating a kinase-like domain in the essential PG biosynthetic protein, MviN. This domain was structurally diverged from active kinases and did not mediate phosphotransfer. Threonine phosphorylation of the pseudokinase domain recruited the FhaA protein through its forkhead-associated (FHA) domain. The crystal structure of this phosphorylated pseudokinase-FHA domain complex revealed the basis of FHA domain recognition, which included unexpected contacts distal to the phosphorylated threonine. Conditional degradation of these proteins in mycobacteria demonstrated that MviN was essential for growth and PG biosynthesis and that FhaA regulated these processes at the cell poles and septum. Controlling this spatially localized PG regulatory complex is only one of several cellular roles ascribed to PknB, suggesting that the capacity to coordinate signaling across multiple processes is an important feature conserved between eukaryotic and prokaryotic STPK networks.
Collapse
Affiliation(s)
- Christine L Gee
- Department of Molecular and Cell Biology, QB3 Institute, University of California, Berkeley, Berkeley, CA 94720-3220, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Zhang J, Petit CM, King DS, Lee AL. Phosphorylation of a PDZ domain extension modulates binding affinity and interdomain interactions in postsynaptic density-95 (PSD-95) protein, a membrane-associated guanylate kinase (MAGUK). J Biol Chem 2011; 286:41776-41785. [PMID: 21965656 DOI: 10.1074/jbc.m111.272583] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Postsynaptic density-95 is a multidomain scaffolding protein that recruits glutamate receptors to postsynaptic sites and facilitates signal processing and connection to the cytoskeleton. It is the leading member of the membrane-associated guanylate kinase family of proteins, which are defined by the PSD-95/Discs large/ZO-1 (PDZ)-Src homology 3 (SH3)-guanylate kinase domain sequence. We used NMR to show that phosphorylation of conserved tyrosine 397, which occurs in vivo and is located in an atypical helical extension (α3), initiates a rapid equilibrium of docked and undocked conformations. Undocking reduced ligand binding affinity allosterically and weakened the interaction of PDZ3 with SH3 even though these domains are separated by a ~25-residue linker. Additional phosphorylation at two linker sites further disrupted the interaction, implicating α3 and the linker in tuning interdomain communication. These experiments revealed a novel mode of regulation by a detachable PDZ element and offer a first glimpse at the dynamic interaction of PDZ and SH3-guanylate kinase domains in membrane-associated guanylate kinases.
Collapse
Affiliation(s)
- Jun Zhang
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Chad M Petit
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599
| | - David S King
- Howard Hughes Medical Institute Mass Spectrometry Laboratory and Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
| | - Andrew L Lee
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599; Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599.
| |
Collapse
|
13
|
Lombana TN, Echols N, Good MC, Thomsen ND, Ng HL, Greenstein AE, Falick AM, King DS, Alber T. Allosteric activation mechanism of the Mycobacterium tuberculosis receptor Ser/Thr protein kinase, PknB. Structure 2011; 18:1667-77. [PMID: 21134645 DOI: 10.1016/j.str.2010.09.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 07/29/2010] [Accepted: 09/03/2010] [Indexed: 01/09/2023]
Abstract
The essential Mycobacterium tuberculosis Ser/Thr protein kinase (STPK), PknB, plays a key role in regulating growth and division, but the structural basis of activation has not been defined. Here, we provide biochemical and structural evidence that dimerization through the kinase-domain (KD) N-lobe activates PknB by an allosteric mechanism. Promoting KD pairing using a small-molecule dimerizer stimulates the unphosphorylated kinase, and substitutions that disrupt N-lobe pairing decrease phosphorylation activity in vitro and in vivo. Multiple crystal structures of two monomeric PknB KD mutants in complex with nucleotide reveal diverse inactive conformations that contain large active-site distortions that propagate > 30 Å from the mutation site. These results define flexible, inactive structures of a monomeric bacterial receptor KD and show how "back-to-back" N-lobe dimerization stabilizes the active KD conformation. This general mechanism of bacterial receptor STPK activation affords insights into the regulation of homologous eukaryotic kinases that form structurally similar dimers.
Collapse
Affiliation(s)
- T Noelle Lombana
- Department of Molecular and Cell Biology, QB3 Institute, University of California, Berkeley, CA 94720-3200, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Berhanu A, King DS, Mosier S, Jordan R, Jones KF, Hruby DE, Grosenbach DW. Impact of ST-246® on ACAM2000™ smallpox vaccine reactogenicity, immunogenicity, and protective efficacy in immunodeficient mice. Vaccine 2010; 29:289-303. [PMID: 21036130 DOI: 10.1016/j.vaccine.2010.10.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 09/29/2010] [Accepted: 10/13/2010] [Indexed: 11/16/2022]
Abstract
Although a highly effective vaccine against smallpox, vaccinia virus (VV) is not without adverse events, some of which can be life-threatening, particularly in immunocompromised individuals. We have recently demonstrated that the immunogenicity and protective efficacy of Dryvax(®) in immunocompetent mice is preserved even when co-administered with ST-246, an orally bioavailable small-molecule inhibitor of orthopoxvirus egress and dissemination. In addition, ST-246 markedly reduced the reactogenicity of the smallpox vaccine ACAM2000 and the highly neurovirulent VV strain Western Reserve (VV-WR). Here, we evaluated the impact of ST-246 co-administration on ACAM2000 reactogenicity, immunogenicity, and protective efficacy in seven murine models of varying degrees of humoral and cellular immunodeficiency: BALB/c and B-cell deficient (JH-KO) mice depleted of CD4(+) or CD8(+) or both subsets of T cells. We observed that ST-246 reduced vaccine lesion severity and time to complete resolution in all of the immunodeficient models examined, except in those lacking both CD4(+) and CD8(+) T cells. Although VV-specific humoral responses were moderately reduced by ST-246 treatment, cellular responses were generally comparable or slightly enhanced at both 1 and 6 months post-vaccination. Most importantly, in those models in which vaccination given alone conferred protection against lethal VV challenge, similar levels of protection were observed at both time points when vaccination was given with ST-246. These data suggest that, with the exception of individuals with irreversible, combined CD4(+) and CD8(+) T-cell deficiency, ST-246 co-administered at the time of vaccination may help reduce vaccine reactogenicity--even in those lacking humoral immunity--without impeding the induction of protective immunity.
Collapse
Affiliation(s)
- Aklile Berhanu
- SIGA Technologies, Inc., 4575 SW Research Way, Suite 230, Corvallis, OR 97333, USA
| | | | | | | | | | | | | |
Collapse
|
15
|
King DS, Bollenbacher WE, Borst DW, Vedeckis WV, O'connor JD, Ittycheriah PI, Gilbert LI. The Secretion of alpha-Ecdysone by the Prothoracic Glands of Manduca sexta In Vitro. Proc Natl Acad Sci U S A 2010; 71:793-6. [PMID: 16592146 PMCID: PMC388100 DOI: 10.1073/pnas.71.3.793] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Prothoracic glands of tobacco hornworm larvae cultured in vitro secrete into the culture medium a substance which was active in ecdysone bioassays and determined to be ecdysone-like by radioimmunoassay. The prothoracic glands appear to be the sole source of this substance. The material was identified as alpha-ecdysone by thin-layer, gas-liquid, and high-resolution liquid chromatography and mass spectrometry. No other active moulting principles were present in the medium. It appears that the prothoracic gland secretes a prohormone, alpha-ecdysone, which is subsequently converted into the active moulting hormone, beta-ecdysone, in other insect tissues.
Collapse
Affiliation(s)
- D S King
- Biochemistry Department, Zoëcon Corporation, Palo Alto, California 94304
| | | | | | | | | | | | | |
Collapse
|
16
|
Lin IJ, Xia B, King DS, Machonkin TE, Westler WM, Markley JL. Hyperfine-shifted (13)C and (15)N NMR signals from Clostridium pasteurianum rubredoxin: extensive assignments and quantum chemical verification. J Am Chem Soc 2010; 131:15555-63. [PMID: 19799419 PMCID: PMC2766250 DOI: 10.1021/ja905928x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Stable isotope-labeling methods, coupled with novel techniques for detecting fast-relaxing NMR signals, now permit detailed investigations of paramagnetic centers of metalloproteins. We have utilized these advances to carry out comprehensive assignments of the hyperfine-shifted 13C and 15N signals of the rubredoxin from Clostridium pasteurianum (CpRd) in both its oxidized and reduced states. We used residue-specific labeling (by chemical synthesis) and residue-type-selective labeling (by biosynthesis) to assign signals detected by one-dimensional 15N NMR spectroscopy, to nitrogen atoms near the iron center. We refined and extended these 15N assignments to the adjacent carbonyl carbons by means of one-dimensional 13C[15N] decoupling difference experiments. We collected paramagnetic-optimized SuperWEFT 13C[13C] constant time COSY (SW-CT-COSY) data to complete the assignment of 13C signals of reduced CpRd. By following these 13C signals as the protein was gradually oxidized, we transferred these assignments to carbons in the oxidized state. We have compared these assignments with hyperfine chemical shifts calculated from available X-ray structures of CpRd in its oxidized and reduced forms. The results allow the evaluation of the X-ray structural models as representative of the solution structure of the protein, and they provide a framework for future investigation of the active site of this protein. The methods developed here should be applicable to other proteins that contain a paramagnetic center with high spin and slow electron exchange.
Collapse
Affiliation(s)
- I-Jin Lin
- Graduate Program in Biophysics, University of Wisconsin-Madison, 433 Babcock Drive, Madison, Wisconsin 53706, USA
| | | | | | | | | | | |
Collapse
|
17
|
Abstract
AIMS To (i) develop a protocol that would eliminate or greatly reduce sporulation within Bacillus anthracis vegetative cells, and (ii) harvest an adequate number of cells and sufficient DNA suitable for molecular methods including Riboprint analysis and pulse field gel electrophoresis (PFGE). METHODS AND RESULTS Seven strains of B. anthracis (Ames, French B2, Heluky, Kruger, Pasteur, Sterne, and Vollum) were grown at 37, 42 and 45 degrees C under normal air, enhanced CO(2), microaerophilic, and anaerobic conditions on solid media and subcultured in two broths with and without supplements. The bacterial cells were centrifuged and washed. Slides made from the cell pellets were stained with Malachite Green and observed for the presence of spores. Cell preparations were subjected to 80 degrees C for 30 min and processed for and analysed by either Riboprinte or PFGE. Multiple pellets of each strain were processed, stained, placed onto solid culture media, incubated for 7 days and observed for growth. The cell preparations yielded clear and reproducible results with both molecular methods. None of the cell preparations yielded growth on the culture media. CONCLUSIONS This method eliminated viable spores in cell preparations of B. anthracis, yet still allowed the growth of vegetative cells to provide sufficient DNA suitable for analysis by Riboprinter and PFGE. SIGNIFICANCE AND IMPACT OF THE STUDY This method will provide safe cell preparations, prevent instrument contamination, and may be useful for other aerobic and anaerobic spore-formers.
Collapse
Affiliation(s)
- D S King
- Center for Biological Defense, College of Public Health, University of South Florida, Tampa, FL 33612, USA
| | | | | | | |
Collapse
|
18
|
Fujita Y, Wideman RD, Speck M, Asadi A, King DS, Webber TD, Haneda M, Kieffer TJ. Incretin release from gut is acutely enhanced by sugar but not by sweeteners in vivo. Am J Physiol Endocrinol Metab 2009; 296:E473-9. [PMID: 19106249 DOI: 10.1152/ajpendo.90636.2008] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are released during meals from endocrine cells located in the gut mucosa and stimulate insulin secretion from pancreatic beta-cells in a glucose-dependent manner. Although the gut epithelium senses luminal sugars, the mechanism of sugar sensing and its downstream events coupled to the release of the incretin hormones are not clearly elucidated. Recently, it was reported that sucralose, a sweetener that activates the sweet receptors of taste buds, triggers incretin release from a murine enteroendocrine cell line in vitro. We confirmed that immunoreactivity of alpha-gustducin, a key G-coupled protein involved in taste sensing, is sometimes colocalized with GIP in rat duodenum. We investigated whether secretion of incretins in response to carbohydrates is mediated via taste receptors by feeding rats the sweet-tasting compounds saccharin, acesulfame potassium, d-tryptophan, sucralose, or stevia. Oral gavage of these sweeteners did not reduce the blood glucose excursion to a subsequent intraperitoneal glucose tolerance test. Neither oral sucralose nor oral stevia reduced blood glucose levels in Zucker diabetic fatty rats. Finally, whereas oral glucose increased plasma GIP levels approximately 4-fold and GLP-1 levels approximately 2.5-fold postadministration, none of the sweeteners tested significantly increased levels of these incretins. Collectively, our findings do not support the concept that release of incretins from enteroendocrine cells is triggered by carbohydrates via a pathway identical to the sensation of "sweet taste" in the tongue.
Collapse
Affiliation(s)
- Yukihiro Fujita
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Higginson CI, Wheelock VL, Levine D, King DS, Pappas CTE, Sigvardt KA. The clinical significance of neuropsychological changes following bilateral subthalamic nucleus deep brain stimulation for Parkinson's disease. J Clin Exp Neuropsychol 2008; 31:65-72. [DOI: 10.1080/13803390801982734] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Christopher I. Higginson
- a Loyola College in Maryland , Baltimore, MD, USA
- b Center for Neuroscience , UC Davis , Davis, CA, USA
| | - Vicki L. Wheelock
- c Department of Neurology , UC Davis Medical Center , Sacramento, CA, USA
- d Clinical Functional Neuroscience Department , Kaiser Permanente Northern California , Sacramento, CA, USA
| | - Dawn Levine
- d Clinical Functional Neuroscience Department , Kaiser Permanente Northern California , Sacramento, CA, USA
| | - David S. King
- d Clinical Functional Neuroscience Department , Kaiser Permanente Northern California , Sacramento, CA, USA
| | - Conrad T. E. Pappas
- d Clinical Functional Neuroscience Department , Kaiser Permanente Northern California , Sacramento, CA, USA
| | - Karen A. Sigvardt
- b Center for Neuroscience , UC Davis , Davis, CA, USA
- c Department of Neurology , UC Davis Medical Center , Sacramento, CA, USA
- e VA Northern California Heath Care System , Martinez, CA, USA
| |
Collapse
|
20
|
Fujita Y, Chui JWY, King DS, Zhang T, Seufert J, Pownall S, Cheung AT, Kieffer TJ. Pax6 and Pdx1 are required for production of glucose-dependent insulinotropic polypeptide in proglucagon-expressing L cells. Am J Physiol Endocrinol Metab 2008; 295:E648-57. [PMID: 18593849 DOI: 10.1152/ajpendo.90440.2008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are incretin hormones that play important roles in maintaining glucose homeostasis and are being actively pursued as novel therapeutic agents for diabetes. GIP is produced by dispersed enteroendocrine cells and interestingly at times is coexpressed with GLP-1. We sought to determine the factors that selectively define GIP- vs. GLP-1-expressing cells. We performed comparative immunostaining of Pax6 and Pdx1 in GIP- and GLP-1-secreting cells. We investigated whether Pax6 and Pdx1 activate the human GIP promoter in control IEC-6 cells and GIP-expressing STC-1 cells. EMSA was performed to assess the binding of these transcription factors to the GIP promoter. Pax6 and Pdx1 consistently colocalized in GIP-immunoreactive cells. Cells that coexpress GIP and GLP-1 were Pax6 and Pdx1 positive, whereas cells expressing only GLP-1 were Pax6 positive but did not express Pdx1. GIP promoter activity was enhanced in IEC-6 cells by exogenous Pax6 or Pdx1 and diminished in STC-1 cells by inhibition of endogenous Pax6 or Pdx1 by dominant-negative forms. Promoter truncation analysis revealed a major loss of promoter activity when the sequence between -184 to -145 bp was deleted. EMSA studies indicated that Pax6 and Pdx1 bind to this proximal sequence of the human GIP promoter. Our findings indicate that concomitant expression of Pax6 and Pdx1 is important for GIP expression. Our results also suggest that the presence of Pdx1 defines whether GLP-1-expressing gastrointestinal L cells also coexpress GIP.
Collapse
Affiliation(s)
- Yukihiro Fujita
- Department of Cellular and Physiological Sciences, Univ. of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Carlson BL, Ballister ER, Skordalakes E, King DS, Breidenbach MA, Gilmore SA, Berger JM, Bertozzi CR. Function and structure of a prokaryotic formylglycine-generating enzyme. J Biol Chem 2008; 283:20117-25. [PMID: 18390551 PMCID: PMC2459300 DOI: 10.1074/jbc.m800217200] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Type I sulfatases require an unusual co- or post-translational modification for their activity in hydrolyzing sulfate esters. In eukaryotic sulfatases, an active site cysteine residue is oxidized to the aldehyde-containing Cα-formylglycine residue by the formylglycine-generating enzyme (FGE). The machinery responsible for sulfatase activation is poorly understood in prokaryotes. Here we describe the identification of a prokaryotic FGE from Mycobacterium tuberculosis. In addition, we solved the crystal structure of the Streptomyces coelicolor FGE homolog to 2.1Å resolution. The prokaryotic homolog exhibits remarkable structural similarity to human FGE, including the position of catalytic cysteine residues. Both biochemical and structural data indicate the presence of an oxidized cysteine modification in the active site that may be relevant to catalysis. In addition, we generated a mutant M. tuberculosis strain lacking FGE. Although global sulfatase activity was reduced in the mutant, a significant amount of residual sulfatase activity suggests the presence of FGE-independent sulfatases in this organism.
Collapse
Affiliation(s)
- Brian L Carlson
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California Berkeley, Berkeley, CA 94720, USA
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Higginson CI, Wheelock VL, Levine D, King DS, Pappas CTE, Sigvardt KA. Cognitive deficits in essential tremor consistent with frontosubcortical dysfunction. J Clin Exp Neuropsychol 2008; 30:760-5. [PMID: 18608666 DOI: 10.1080/13803390701754738] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Essential tremor (ET) is increasingly thought to involve a heterogeneous group of patients, with some also exhibiting symptoms of Parkinson's disease (PD), including cognitive deficits. The goal of this study was to utilize a broad battery of neuropsychological measures to compare the cognitive function of 33 ET patients with that of 33 matched PD patients and 21 normal controls. Results indicated that the ET group performed significantly worse than controls across multiple cognitive domains, but performed remarkably similar to PD patients, consistent with frontosubcortical dysfunction.
Collapse
|
23
|
Kelly DR, Baker SC, King DS, de Silva DS, Lord G, Taylor JP. Studies of nitrile oxide cycloadditions, and the phenolic oxidative coupling of vanillin aldoxime by Geobacillus sp. DDS012 from Italian rye grass silage. Org Biomol Chem 2008; 6:787-96. [PMID: 18264580 DOI: 10.1039/b716915a] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
During studies directed towards the discovery of nitrile hydrolysing enzymes from thermophiles, vanillin aldoxime was incubated with the thermophilic organism, Geobacillus sp. DDS012 isolated from Italian rye grass (Lolium multiflorum) silage. The predominant product was a dihydro-dimer, which could only be characterised by LC-MS. This was initially imagined to be the product of cycloaddition of vanillin aldoxime with the corresponding nitrile oxide, but preparation of the supposed adduct and model studies excluded this possibility. The rate constant for the second order dimerisation of 4-O-acetyl vanillin nitrile oxide was measured (1.21 x 10(-4) M(-1) s(-1), 0.413 M, 25 degrees C) and the (13)C-NMR signal for the nitrile oxide carbon was observed (delta(C) 34.4, br. t (1)J(13)C,(14)N circa 50 Hz). Treatment of vanillin aldoxime with potassium persulfate and iron sulfate gave material with the same LC-MS properties as the natural product, which is therefore identified as 5,5'-dehydro-di-(vanillin aldoxime) 1d formed by phenolic oxidative coupling.
Collapse
Affiliation(s)
- David R Kelly
- The Tatem Laboratories, School of Chemistry, Cardiff University, Cardiff, CF10 3AT, UK.
| | | | | | | | | | | |
Collapse
|
24
|
Grosenbach DW, Jordan R, King DS, Berhanu A, Warren TK, Kirkwood-Watts DL, Tyavanagimatt S, Tan Y, Wilson RL, Jones KF, Hruby DE. Immune responses to the smallpox vaccine given in combination with ST-246, a small-molecule inhibitor of poxvirus dissemination. Vaccine 2007; 26:933-46. [PMID: 18226434 PMCID: PMC2757089 DOI: 10.1016/j.vaccine.2007.11.095] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Revised: 10/26/2007] [Accepted: 11/29/2007] [Indexed: 11/24/2022]
Abstract
The re-emerging threat of smallpox and the emerging threat of monkeypox highlight the need for effective poxvirus countermeasures. Currently approved smallpox vaccines have unacceptable safety profiles and, consequently, the general populace is no longer vaccinated, leading to an increasingly susceptible population. ST-246, a small-molecule inhibitor of poxvirus dissemination, has been demonstrated in various animal models to be safe and effective in preventing poxviral disease. This suggests that it may also be used to improve the safety of the traditional smallpox vaccine provided that it does not inhibit vaccine-induced protective immunity. In this study, we compared the immune responses elicited by the smallpox vaccine alone or in combination with ST-246 in mice. Normal lesion formation following dermal scarification with the attenuated New York City Board of Health strain (Dryvax), commonly referred to as a vaccine “take”, was not inhibited although severe lesions and systemic disease due to vaccination with the virulent Western Reserve (VV-WR) strain were prevented. The vaccine given with ST-246 did not affect cellular immune responses or neutralizing antibody titers although anti-vaccinia ELISA titers were slightly reduced. Vaccination in combination with ST-246 provided equivalent short- and long-term protection against lethal intranasal challenge with VV-WR when compared to vaccine alone. These results suggest that ST-246 does not compromise protective immunity elicited by the vaccine and provide the basis for future studies examining the efficacy of ST-246 in preventing or treating adverse events due to vaccination.
Collapse
Affiliation(s)
- Douglas W Grosenbach
- SIGA Technologies, 4575 SW Research Way, Suite 230, Corvallis, OR 97333, United States
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Affiliation(s)
- Zachary A. Knight
- Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94107
| | - Jennifer L. Garrison
- Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94107
| | - Karina Chan
- Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94107
| | - David S. King
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, California 94720
| | - Kevan M. Shokat
- Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94107
| |
Collapse
|
26
|
Abstract
The yeast DASH complex is a heterodecameric component of the kinetochore necessary for accurate chromosome segregation. DASH forms closed rings around microtubules with a large gap between the DASH ring and the microtubule cylinder. We characterized the microtubule-binding properties of limited proteolysis products and subcomplexes of DASH, thus identifying candidate polypeptide extensions involved in establishing the DASH-microtubule interface. The acidic C-terminal extensions of tubulin subunits are not essential for DASH binding. We also measured the molecular mass of DASH rings on microtubules with scanning transmission electron microscopy and found that approximately 25 DASH heterodecamers assemble to form each ring. Dynamic association and relocation of multiple flexible appendages of DASH may allow the kinetochore to translate along the microtubule surface.
Collapse
Affiliation(s)
- JJ L. Miranda
- *Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138
| | - David S. King
- Department of Molecular and Cell Biology, and Howard Hughes Medical Institute, University of California, Berkeley, CA 94720; and
| | - Stephen C. Harrison
- Department of Biological Chemistry and Molecular Pharmacology, and Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115
| |
Collapse
|
27
|
King DS, Cavanagh RR. Molecular Desorption from Solid Surfaces: Laser Diagnostics and Chemical Dynamics. Advances in Chemical Physics 2007. [DOI: 10.1002/9780470141250.ch2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
28
|
Greenstein AE, Echols N, Lombana TN, King DS, Alber T. Allosteric activation by dimerization of the PknD receptor Ser/Thr protein kinase from Mycobacterium tuberculosis. J Biol Chem 2007; 282:11427-35. [PMID: 17242402 DOI: 10.1074/jbc.m610193200] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To define how extracellular signals activate bacterial receptor Ser/Thr protein kinases, we characterized the regulatory functions of a weak dimer interface identified in the Mycobacterium tuberculosis PknB and PknE receptor kinases. Sequence comparisons revealed that the analogous interface is conserved in PknD orthologs from diverse bacterial species. To analyze the roles of dimerization, we constructed M. tuberculosis PknD kinase domain (KD) fusion proteins that formed dimers upon addition of rapamycin. Dimerization of unphosphorylated M. tuberculosis PknD KD fusions stimulated phosphorylation activity. Mutations in the dimer interface reduced this activation, limited autophosphorylation, and altered substrate specificity. In contrast, an inactive catalytic site mutant retained the ability to stimulate the wild-type KD by dimerization. These results support the idea that dimer formation allosterically activates unphosphorylated PknD. The phosphorylated PknD KD was fully active even in the absence of dimerization, suggesting that phosphorylation provides an additional regulatory mechanism. The conservation of analogous dimers in diverse prokaryotic and eukaryotic Ser/Thr protein kinases implies that this mechanism of protein kinase regulation is ancient and broadly distributed.
Collapse
Affiliation(s)
- Andrew E Greenstein
- Department of Molecular and Cell Biology, and Howard Hughes Medical Institute Mass Spectrometry Laboratory, University of California, Berkeley, California 94720-3206, USA
| | | | | | | | | |
Collapse
|
29
|
Toshima JY, Toshima J, Kaksonen M, Martin AC, King DS, Drubin DG. Spatial dynamics of receptor-mediated endocytic trafficking in budding yeast revealed by using fluorescent alpha-factor derivatives. Proc Natl Acad Sci U S A 2006; 103:5793-8. [PMID: 16574772 PMCID: PMC1458652 DOI: 10.1073/pnas.0601042103] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Much progress defining the order and timing of endocytic internalization events has come as a result of real-time, live-cell fluorescence microscopy. Although the availability of numerous endocytic mutants makes yeast an especially valuable organism for functional analysis of endocytic dynamics, a serious limitation has been the lack of a fluorescent cargo for receptor-mediated endocytosis. We have now synthesized biologically active fluorescent mating-pheromone derivatives and demonstrated that receptor-mediated endocytosis in budding yeast occurs via the clathrin- and actin-mediated endocytosis pathway. We found that endocytic proteins first assemble into patches on the plasma membrane, and then alpha-factor associates with the patches. Internalization occurs next, concomitant with actin assembly at patches. Additionally, endocytic vesicles move toward early endosomes on actin cables. Early endosomes also associate with actin cables, and they actively move toward endocytic sites to capture vesicles being released from the plasma membrane. Thus, endocytic vesicle formation and capture of the newly released vesicles by early endosomes occur in a highly concerted manner, mediated by the actin cytoskeleton.
Collapse
Affiliation(s)
- Junko Y. Toshima
- *Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202; and
| | - Jiro Toshima
- *Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202; and
| | - Marko Kaksonen
- *Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202; and
| | - Adam C. Martin
- *Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202; and
| | - David S. King
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720-3202
| | - David G. Drubin
- *Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202; and
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
30
|
Wilson RL, Brown LL, Kirkwood-Watts D, Warren TK, Lund SA, King DS, Jones KF, Hruby DE. Listeria monocytogenes 10403S HtrA is necessary for resistance to cellular stress and virulence. Infect Immun 2006; 74:765-8. [PMID: 16369036 PMCID: PMC1346606 DOI: 10.1128/iai.74.1.765-768.2006] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The HtrA serine protease has been shown to be essential for bacterial virulence and for survival after exposure to many types of environmental and cellular stresses. A Listeria monocytogenes 10403S htrA mutant was found to be sensitive to oxidative and puromycin-induced stress at high temperatures, showed a reduced ability to form biofilms, and was attenuated for virulence in mice.
Collapse
Affiliation(s)
- Rebecca L Wilson
- SIGA Technologies, 4575 NW Research Way, Corvallis, OR 97330, USA
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Lowery TJ, Garcia S, Chavez L, Ruiz EJ, Wu T, Brotin T, Dutasta JP, King DS, Schultz PG, Pines A, Wemmer DE. Optimization of Xenon Biosensors for Detection of Protein Interactions. Chembiochem 2005; 7:65-73. [PMID: 16342304 DOI: 10.1002/cbic.200500327] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Hyperpolarized 129Xe NMR spectroscopy can detect the presence of specific low-concentration biomolecular analytes by means of a xenon biosensor that consists of a water-soluble, targeted cryptophane-A cage that encapsulates the xenon. In this work, we use the prototypical biotinylated xenon biosensor to determine the relationship between the molecular composition of the xenon biosensor and the characteristics of protein-bound resonances. The effects of diastereomer overlap, dipole-dipole coupling, chemical-shift anisotropy, xenon exchange, and biosensor conformational exchange on the protein-bound biosensor signal were assessed. It was found that an optimal protein-bound biosensor signal can be obtained by minimizing the number of biosensor diastereomers and using a flexible linker of appropriate length. Both the line width and sensitivity of chemical shift to protein binding of the xenon biosensor were found to be inversely proportional to linker length.
Collapse
Affiliation(s)
- Thomas J Lowery
- Department of Chemistry, University of California at Berkeley, Berkeley, CA 94720, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Bolken TC, Laquerre S, Zhang Y, Bailey TR, Pevear DC, Kickner SS, Sperzel LE, Jones KF, Warren TK, Amanda Lund S, Kirkwood-Watts DL, King DS, Shurtleff AC, Guttieri MC, Deng Y, Bleam M, Hruby DE. Identification and characterization of potent small molecule inhibitor of hemorrhagic fever New World arenaviruses. Antiviral Res 2005; 69:86-97. [PMID: 16343651 PMCID: PMC7114356 DOI: 10.1016/j.antiviral.2005.10.008] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 10/27/2005] [Accepted: 10/27/2005] [Indexed: 11/18/2022]
Abstract
Category A arenaviruses as defined by the National Institute of Allergy and Infectious Diseases (NIAID) are human pathogens that could be weaponized by bioterrorists. Many of these deadly viruses require biosafety level-4 (BSL-4) containment for all laboratory work, which limits traditional laboratory high-throughput screening (HTS) for identification of small molecule inhibitors. For those reasons, a related BSL-2 New World arenavirus, Tacaribe virus, 67-78% identical to Junín virus at the amino acid level, was used in a HTS campaign where approximately 400,000 small molecule compounds were screened in a Tacaribe virus-induced cytopathic effect (CPE) assay. Compounds identified in this screen showed antiviral activity and specificity against not only Tacaribe virus, but also the Category A New World arenaviruses (Junín, Machupo, and Guanarito). Drug resistant variants were isolated, suggesting that these compounds act through inhibition of a viral protein, the viral glycoprotein (GP2), and not through cellular toxicity mechanisms. A lead compound, ST-294, has been chosen for drug development. This potent and selective compound, with good bioavailability, demonstrated protective anti-viral efficacy in a Tacaribe mouse challenge model. This series of compounds represent a new class of inhibitors that may warrant further development for potential inclusion in a strategic stockpile.
Collapse
Affiliation(s)
- Tove C Bolken
- SIGA Technologies Inc., 4575 SW Research Way, Corvallis, OR 97333, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Seeliger MA, Young M, Henderson MN, Pellicena P, King DS, Falick AM, Kuriyan J. High yield bacterial expression of active c-Abl and c-Src tyrosine kinases. Protein Sci 2005; 14:3135-9. [PMID: 16260764 PMCID: PMC2253236 DOI: 10.1110/ps.051750905] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The Abl and Src tyrosine kinases are key signaling proteins that are of considerable interest as drug targets in cancer and many other diseases. The regulatory mechanisms that control the activity of these proteins are complex, and involve large-scale conformational changes in response to phosphorylation and other modulatory signals. The success of the Abl inhibitor imatinib in the treatment of chronic myelogenous leukemia has shown the potential of kinase inhibitors, but the rise of drug resistance in patients has also shown that drugs with alternative modes of binding to the kinase are needed. The detailed understanding of mechanisms of protein-drug interaction and drug resistance through biophysical methods demands a method for the production of active protein on the milligram scale. We have developed a bacterial expression system for the kinase domains of c-Abl and c-Src, which allows for the quick expression and purification of active wild-type and mutant kinase domains by coexpression with the YopH tyrosine phosphatase. This method makes practical the use of isotopic labeling of c-Abl and c-Src for NMR studies, and is also applicable for constructs containing the SH2 and SH3 domains of the kinases.
Collapse
Affiliation(s)
- Markus A Seeliger
- Department of Molecular and Cell Biology, 16 Barker Hall, University of California, Berkeley, CA 94720-3202, USA
| | | | | | | | | | | | | |
Collapse
|
34
|
Han SI, Garcia S, Lowery TJ, Ruiz EJ, Seeley JA, Chavez L, King DS, Wemmer DE, Pines A. NMR-Based Biosensing with Optimized Delivery of Polarized129Xe to Solutions. Anal Chem 2005; 77:4008-12. [PMID: 15987104 DOI: 10.1021/ac0500479] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Laser-enhanced (LE) 129Xe nuclear magnetic resonance (NMR) is an exceptional tool for sensing extremely small physical and chemical changes; however, the difficult mechanics of bringing polarized xenon and samples of interest together have limited applications, particularly to biological molecules. Here we present a method for accomplishing solution 129Xe biosensing based on flow (bubbling) of LE 129Xe gas through a solution in situ in the NMR probe, with pauses for data acquisition. This overcomes fundamental limitations of conventional solution-state LE 129Xe NMR, e.g., the difficulty in transferring hydrophobic xenon into aqueous environments, and the need to handle the sample to refresh LE 129Xe after an observation pulse depletes polarization. With this new method, we gained a factor of >100 in sensitivity due to improved xenon transfer to the solution and the ability to signal average by renewing the polarized xenon. Polarized xenon in biosensors was detected at very low concentrations, </=250 nanomolar, while retaining all the usual information from NMR. This approach can be used to simultaneously detect multiple sensors with different chemical shifts and is also capable of detecting signals from opaque, heterogeneous samples, which is a unique advantage over optical methods. This general approach is adaptable for sensing minute quantities of xenon in heterogeneous in vitro samples, in miniaturized devices and should be applicable to certain in-vivo environments.
Collapse
Affiliation(s)
- Song-I Han
- Material Sciences and Physical Biosciences Divisions, Lawrence Berkeley National Laboratory, and Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA. songi@ chem.ucsb.edu
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Schneider EL, King DS, Marletta MA. Amino acid substitution and modification resulting from Escherichia coli expression of recombinant Plasmodium falciparum histidine-rich protein II. Biochemistry 2005; 44:987-95. [PMID: 15654755 DOI: 10.1021/bi048571h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The histidine-rich protein II (HRP II) from Plasmodium falciparum is an unusual protein composed of 40% alanine, 36% histidine, and 11% aspartate residues. Expression of HRP II in Escherichia coli results in the isolation of a heterogeneous protein. Mass spectrometry reveals a reduction in mass by multiples of 9 Da from the expected molecular mass that can be attributed to the substitution of glutamine for some histidine residues in the sequence. The extent of the glutamine for histidine substitution can be reduced by slowing the expression rate. Mass spectral analysis of HRP II also revealed alpha-amino methylation of the N-terminal alanine residue of HRP II.
Collapse
Affiliation(s)
- Eric L Schneider
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720-1460, USA
| | | | | |
Collapse
|
36
|
Zhang Z, Alfonta L, Tian F, Bursulaya B, Uryu S, King DS, Schultz PG. Selective incorporation of 5-hydroxytryptophan into proteins in mammalian cells. Proc Natl Acad Sci U S A 2004; 101:8882-7. [PMID: 15187228 PMCID: PMC428441 DOI: 10.1073/pnas.0307029101] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2003] [Indexed: 11/18/2022] Open
Abstract
An orthogonal tryptophanyl-transfer RNA (tRNA) synthetase (TrpRS)-mutant opal suppressor tRNA(Trp) (mutRNA(UCA)(Trp)) pair was generated for use in mammalian cells. The anticodon loop of the Bacillus subtilis tRNA(Trp) was mutated to UCA, three positions in the D arm were mutated to generate an internal promoter sequence, and the mutRNA(UCA)(Trp) gene was inserted between the 5' and 3' flanking sequences of the tRNA(Trp-1) gene from Arabidopsis to enhance its expression in mammalian cells. In vitro aminoacylation assays and in vivo opal suppression assays showed that B. subtilis TrpRS (BsTrpRS) charges only the cognate mutRNA(UCA)(Trp) and no endogenous mammalian tRNAs. Similarly, the mutRNA(UCA)(Trp) is specifically charged by B. subtilis TrpRS and not by endogenous synthetases in mammalian cells. Site-directed mutagenesis was then used to alter the specificity of BsTrpRS to uniquely charge 5-hydoxy-l-tryptophan. The resulting mutant BsTrpRS-mutRNA(UCA)(Trp) pair allows the efficient and selective incorporation of 5-hydroxy-l-tryptophan into mammalian proteins in response to the codon, TGA. This amino acid can be used as a fluorescence probe and also undergoes electrochemical oxidation in situ to generate an efficient protein crosslinking.
Collapse
Affiliation(s)
- Zhiwen Zhang
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | | | | | | | | | | |
Collapse
|
37
|
Abstract
With few exceptions the genetic codes of all known organisms encode the same 20 amino acids, yet all that is required to add a new building block are a unique tRNA/aminoacyl-tRNA synthetase pair, a source of the amino acid, and a unique codon that specifies the amino acid. For example, the amber nonsense codon, TAG, together with orthogonal Methanococcus jannaschii or Escherichia coli tRNA/synthetase pairs have been used to genetically encode a variety of unnatural amino acids in E. coli and yeast, respectively. However, the availability of noncoding triplet codons ultimately limits the number of amino acids encoded by any organism. Here, we report the design and generation of an orthogonal synthetase/tRNA pair derived from archaeal tRNA(Lys) sequences that efficiently and selectively incorporates an unnatural amino acid into proteins in response to the quadruplet codon, AGGA. Frameshift suppression with L-homoglutamine (hGln) does not significantly affect protein yields or cell growth rates and is mutually orthogonal with amber suppression, permitting the simultaneous incorporation of two unnatural amino acids, hGln and O-methyl-L-tyrosine, at distinct positions within myoglobin. This work suggests that neither the number of available triplet codons nor the translational machinery itself represents a significant barrier to further expansion of the genetic code.
Collapse
Affiliation(s)
- J Christopher Anderson
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | | | | | | | | | | |
Collapse
|
38
|
Brown GA, Dewey JC, Brunkhorst JA, Vukovich MD, King DS. Changes in serum testosterone and estradiol concentrations following acute androstenedione ingestion in young women. Horm Metab Res 2004; 36:62-6. [PMID: 14983409 DOI: 10.1055/s-2004-814201] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The effect of androstenedione intake on serum hormone concentrations in women is equivocal. Therefore, we examined the hormonal response to androstenedione intake in healthy young (22.1 +/- 0.4 y) women for 4 hours. On day 3 of the follicular phase, subjects ingested placebo, 100, or 300 mg androstenedione in a random, double-blind, cross-over manner. Blood samples were collected before and every 30 min for 240 min after intake. Serum androstenedione concentrations (means +/- SE) increased above basal (6.2 +/- 0.8 nmol/l) from 60-240 min for both 100 mg (22.6 +/- 1.0 nmol/l at 240 min) and 300 mg (28.1 +/- 1.3 nmol/l at 210 min). Androstenedione intake increased serum total testosterone concentrations above basal (1.2 +/- 0.2 nmol/l) from 120-240 min (5.5 +/- 0.9 nmol/l at 210 min) with 100 mg and from 60-240 with 300 mg (10.2 +/- 1.6 nmol/l at 210 min). Androstenedione intake also increased serum estradiol concentrations (basal 191 +/- 24 pmol/l) at 150 min with 100 mg (237 +/- 35 pmol/l) and from 150-240 min with 300 mg (reaching 260 +/- 32 pmol/l at 240 min). These data indicate that, in contrast to men, androstenedione intake in women increases serum testosterone concentrations.
Collapse
Affiliation(s)
- G A Brown
- Exercise Biochemistry Laboratory, Department of Health and Human Performance, Iowa State University, Ames, IA 50011, USA
| | | | | | | | | |
Collapse
|
39
|
Higginson CI, King DS, Levine D, Wheelock VL, Khamphay NO, Sigvardt KA. The relationship between executive function and verbal memory in Parkinson's disease. Brain Cogn 2003; 52:343-52. [PMID: 12907179 DOI: 10.1016/s0278-2626(03)00180-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A growing body of evidence suggests that the various cognitive symptoms found in Parkinson's disease (PD) are secondary to executive dysfunction. Studies addressing this possibility for memory impairment specifically have not included measures of working memory nor have they ruled-out potential mediating variables such as overall level of cognitive impairment or depression. The purpose of this study was to include measures of these variables in determining the relationship between multiple aspects of executive function and delayed verbal recall in 32 idiopathic PD patients. Results were consistent with the original hypothesis and further suggest that working memory is a key factor in recall memory and may mediate the relationship between other executive measures and recall in PD.
Collapse
|
40
|
Radisky ES, King DS, Kwan G, Koshland DE. The role of the protein core in the inhibitory power of the classic serine protease inhibitor, chymotrypsin inhibitor 2. Biochemistry 2003; 42:6484-92. [PMID: 12767231 DOI: 10.1021/bi034275d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A synthetic cyclic peptide, reported to be a tight-binding inhibitor of serine proteases, is instead found to be a good substrate, as is the linear peptide of the same sequence. Both of the peptides, designed to mimic the binding loop of chymotrypsin inhibitor 2 (CI2), were cleaved by subtilisin primarily at the CI2 reactive-site Met-59-Glu-60 bond, revealing that the sequence, in the absence of the structural context of the inhibitor, provides sufficient specificity for hydrolysis of this bond. Insights from the crystal structure of the CI2/subtilisin complex, together with biochemical analysis of a CI2 Gly-83 deletion mutant, have allowed us to identify key features that make CI2 an effective inhibitor, while the cyclic and linear peptides are substrates.
Collapse
Affiliation(s)
- Evette S Radisky
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
| | | | | | | |
Collapse
|
41
|
Tanaka H, Yoshida T, Miyamoto N, Motoike T, Kurosu H, Shibata K, Yamanaka A, Williams SC, Richardson JA, Tsujino N, Garry MG, Lerner MR, King DS, O'Dowd BF, Sakurai T, Yanagisawa M. Characterization of a family of endogenous neuropeptide ligands for the G protein-coupled receptors GPR7 and GPR8. Proc Natl Acad Sci U S A 2003; 100:6251-6. [PMID: 12719537 PMCID: PMC156358 DOI: 10.1073/pnas.0837789100] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
GPR7 and GPR8 are orphan G protein-coupled receptors that are highly similar to each other. These receptors are expressed predominantly in brain, suggesting roles in central nervous system function. We have purified an endogenous peptide ligand for GPR7 from bovine hypothalamus extracts. This peptide, termed neuropeptide B (NPB), has a C-6-brominated tryptophan residue at the N terminus. It binds and activates human GPR7 or GPR8 with median effective concentrations (EC(50)) of 0.23 nM and 15.8 nM, respectively. In situ hybridization shows distinct localizations of the prepro-NPB mRNA in mouse brain, i.e., in paraventricular hypothalamic nucleus, hippocampus, and several nuclei in midbrain and brainstem. Intracerebroventricular (i.c.v.) injection of NPB in mice induces hyperphagia during the first 2 h, followed by hypophagia. Intracerebroventricular injection of NPB produces analgesia to s.c. formalin injection in rats. Through EST database searches, we identified a putative paralogous peptide. This peptide, termed neuropeptide W (NPW), also has an N-terminal tryptophan residue. Synthetic human NPW binds and activates human GPR7 or GPR8 with EC(50) values of 0.56 nM and 0.51 nM, respectively. The expression of NPW mRNA in mouse brain is confined to specific nuclei in midbrain and brainstem. These findings suggest diverse physiological functions of NPB and NPW in the central nervous system, acting as endogenous ligands on GPR7 andor GPR8.
Collapse
Affiliation(s)
- Hirokazu Tanaka
- Howard Hughes Medical Institute and Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75390-9050, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Huttner IG, Strahl T, Osawa M, King DS, Ames JB, Thorner J. Molecular interactions of yeast frequenin (Frq1) with the phosphatidylinositol 4-kinase isoform, Pik1. J Biol Chem 2003; 278:4862-74. [PMID: 12477731 DOI: 10.1074/jbc.m207920200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Frq1, a 190-residue N-myristoylated calcium-binding protein, associates tightly with the N terminus of Pik1, a 1066-residue phosphatidylinositol 4-kinase. Deletion analysis of an Frq1-binding fragment, Pik1-(10-192), showed that residues within 80-192 are necessary and sufficient for Frq1 association in vitro. A synthetic peptide (residues 151-199) competed for binding of [(35)S]Pik1-(10-192) to bead-immobilized Frq1, whereas shorter peptides (164-199 and 174-199) did not. Correspondingly, a deletion mutant, Pik1(delta152-191), did not co-immunoprecipitate efficiently with Frq1 and did not support growth at elevated temperature. Site-directed mutagenesis of Pik1-(10-192) suggested that recognition determinants lie over an extended region. Titration calorimetry demonstrated that binding of an 83-residue fragment, Pik1-(110-192), or the 151-199 peptide to Frq1 shows high affinity (K(d) approximately 100 nm) and is largely entropic, consistent with hydrophobic interaction. Stoichiometry of Pik1-(110-192) binding to Frq1 was 1:1, as judged by titration calorimetry, by changes in NMR spectrum and intrinsic tryptophan fluorescence, and by light scattering. In cell extracts, Pik1 and Frq1 exist mainly in a heterodimeric complex, as shown by size exclusion chromatography. Cys-15 in Frq1 is not S-palmitoylated, as assessed by mass spectrometry; a Frq1(C15A) mutant and even a non-myristoylated Frq1(G2A,C15A) double mutant rescued the inviability of frq1Delta cells. This study defines the segment of Pik1 required for high affinity binding of Frq1.
Collapse
Affiliation(s)
- Inken G Huttner
- Department of Molecular and Cell Biology, Division of Biochemistry and Molecular Biology, University of California, Berkeley, California 94720-3202, USA
| | | | | | | | | | | |
Collapse
|
43
|
Mehl RA, Anderson JC, Santoro SW, Wang L, Martin AB, King DS, Horn DM, Schultz PG. Generation of a bacterium with a 21 amino acid genetic code. J Am Chem Soc 2003; 125:935-9. [PMID: 12537491 DOI: 10.1021/ja0284153] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have generated a completely autonomous bacterium with a 21 amino acid genetic code. This bacterium can biosynthesize a nonstandard amino acid from basic carbon sources and incorporate this amino acid into proteins in response to the amber nonsense codon. The biosynthetic pathway for the amino acid p-aminophenylalanine (pAF) as well as a unique pAF synthetase and cognate tRNA were added to Escherichia coli. Denaturing gel electrophoresis and mass spectrometric analysis show that pAF is incorporated into myoglobin with fidelity and efficiency rivaling those of the common 20 amino acids. This and other such organisms may provide an opportunity to examine the evolutionary consequences of adding new amino acids to the genetic repertoire, as well as generate proteins with new or enhanced biological functions.
Collapse
Affiliation(s)
- Ryan A Mehl
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Inoue H, Furukawa T, Giannakopoulos S, Zhou S, King DS, Tanese N. Largest subunits of the human SWI/SNF chromatin-remodeling complex promote transcriptional activation by steroid hormone receptors. J Biol Chem 2002; 277:41674-85. [PMID: 12200431 DOI: 10.1074/jbc.m205961200] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mammalian SWI/SNF-related complexes facilitate gene transcription by remodeling chromatin using the energy of ATP hydrolysis. The recruitment of these complexes to promoters remains poorly understood and may involve histone modifications or direct interactions with site-specific transcription factors or other cofactors. Here we report the isolation of two related but distinct cDNA clones, hOsa1 and hOsa2, that encode the largest subunits of human SWI/SNF. hOsa1 is identical to previously reported BAF250, and hOsa2 shares a high degree of sequence similarity with hOsa1. Mass spectrometric analysis, and immunoblotting with antibodies specific to hOsa1 or hOsa2 demonstrate the presence of both proteins in SWI/SNF-A but not in the related polybromo-BRG1-associated factors complex purified from HeLa cells. Co-precipitation studies indicate that hOsa1 and hOsa2 associate with BRG1 and hBRM through the C-terminal domain of hOsa. We define multiple domains within hBRM and BRG1 that interact with the hOsa C terminus. In cultured mammalian cells, hOsa1 and hOsa2 stimulate transcription by the glucocorticoid, estrogen, and androgen receptors. The glucocorticoid receptor-mediated activation is not observed with the C-terminal domain or with the hOsa2 polypeptide lacking the ARID DNA binding domain. These results suggest that hOsa1 and hOsa2 participate in promoting transcriptional activation by the steroid hormone receptors.
Collapse
Affiliation(s)
- Hiroko Inoue
- Department of Microbiology and Kaplan Cancer Center, New York University School of Medicine, New York 10016-6481, USA
| | | | | | | | | | | |
Collapse
|
45
|
Santoro SW, Wang L, Herberich B, King DS, Schultz PG. An efficient system for the evolution of aminoacyl-tRNA synthetase specificity. Nat Biotechnol 2002; 20:1044-8. [PMID: 12244330 DOI: 10.1038/nbt742] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2002] [Accepted: 07/30/2002] [Indexed: 11/09/2022]
Abstract
A variety of strategies to incorporate unnatural amino acids into proteins have been pursued, but all have limitations with respect to technical accessibility, scalability, applicability to in vivo studies, or site specificity of amino acid incorporation. The ability to selectively introduce unnatural functional groups into specific sites within proteins, in vivo, provides a potentially powerful approach to the study of protein function and to large-scale production of novel proteins. Here we describe a combined genetic selection and screen that allows the rapid evolution of aminoacyl-tRNA synthetase substrate specificity. Our strategy involves the use of an "orthogonal" aminoacyl-tRNA synthetase and tRNA pair that cannot interact with any of the endogenous synthetase-tRNA pairs in Escherichia coli. A chloramphenicol-resistance (Cm(r)) reporter is used to select highly active synthetase variants, and an amplifiable fluorescence reporter is used together with fluorescence-activated cell sorting (FACS) to screen for variants with the desired change in amino acid specificity. Both reporters are contained within a single genetic construct, eliminating the need for plasmid shuttling and allowing the evolution to be completed in a matter of days. Following evolution, the amplifiable fluorescence reporter allows visual and fluorimetric evaluation of synthetase activity and selectivity. Using this system to explore the evolvability of an amino acid binding pocket of a tyrosyl-tRNA synthetase, we identified three new variants that allow the selective incorporation of amino-, isopropyl-, and allyl-containing tyrosine analogs into a desired protein. The new enzymes can be used to produce milligram-per-liter quantities of unnatural amino acid-containing protein in E. coli.
Collapse
Affiliation(s)
- Stephen W Santoro
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, SR202, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | | | | | | | | |
Collapse
|
46
|
Chin JW, Martin AB, King DS, Wang L, Schultz PG. Addition of a photocrosslinking amino acid to the genetic code of Escherichiacoli. Proc Natl Acad Sci U S A 2002; 99:11020-4. [PMID: 12154230 PMCID: PMC123203 DOI: 10.1073/pnas.172226299] [Citation(s) in RCA: 516] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2002] [Indexed: 11/18/2022] Open
Abstract
Benzophenones are among the most useful photocrosslinking agents in biology. We have evolved an orthogonal aminoacyl-tRNA synthetase/tRNA pair that makes possible the in vivo incorporation of p-benzoyl-l-phenylalanine into proteins in Escherichia coli in response to the amber codon, TAG. This unnatural amino acid was incorporated with high translational efficiency and fidelity into the dimeric protein glutathione S-transferase. Irradiation resulted in efficient crosslinking (>50%) of the protein subunits. This methodology may prove useful for discovering and defining protein interactions in vitro and in vivo.
Collapse
Affiliation(s)
- Jason W Chin
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | | | | | | | | |
Collapse
|
47
|
Abstract
We report the selection of a new orthogonal aminoacyl tRNA synthetase/tRNA pair for the in vivo incorporation of a photocrosslinker, p-azido-l-phenylalanine, into proteins in response to the amber codon, TAG. The amino acid is incorporated in good yield with high fidelity and can be used to crosslink interacting proteins.
Collapse
Affiliation(s)
- Jason W Chin
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | | | | | | | | | | |
Collapse
|
48
|
|
49
|
Johnsson K, King DS, Schultz PG. Studies on the Mechanism of Action of Isoniazid and Ethionamide in the Chemotherapy of Tuberculosis. J Am Chem Soc 2002. [DOI: 10.1021/ja00122a038] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
50
|
King DS, Stephenson JC. Intrinsic isotopic selectivity factors: carbon dioxide TEA laser photolysis of dichlorodifluoromethane. J Am Chem Soc 2002. [DOI: 10.1021/ja00491a004] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|