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Tang TX, Finkielstein CV, Capelluto DGS. The C-terminal acidic motif of Phafin2 inhibits PH domain binding to phosphatidylinositol 3-phosphate. Biochim Biophys Acta Biomembr 2020; 1862:183230. [PMID: 32126233 DOI: 10.1016/j.bbamem.2020.183230] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 02/15/2020] [Accepted: 02/18/2020] [Indexed: 02/07/2023]
Abstract
Changes in membrane curvature are required to control the function of subcellular compartments; malfunctions of such processes are associated with a wide range of human diseases. Membrane remodeling often depends upon the presence of phosphoinositides, which recruit protein effectors for a variety of cellular functions. Phafin2 is a phosphatidylinositol 3-phosphate (PtdIns3P)-binding effector involved in endosomal and lysosomal membrane-associated signaling. Both the Phafin2 PH and the FYVE domains bind PtdIns3P, although their redundant function in the protein is unclear. Through a combination of lipid-binding assays, we found that, unlike the FYVE domain, recognition of the PH domain to PtdIns3P requires a lipid bilayer. Using site-directed mutagenesis and truncation constructs, we discovered that the Phafin2 FYVE domain is constitutive for PtdIns3P binding, whereas PH domain binding to PtdIns3P is autoinhibited by a conserved C-terminal acidic motif. These findings suggest that binding of the Phafin2 PH domain to PtdIns3P in membrane compartments occurs through a highly regulated mechanism. Potential mechanisms are discussed throughout this report.
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2
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Xiong W, Tang TX, Littleton E, Karcini A, Lazar IM, Capelluto DGS. Preferential phosphatidylinositol 5-phosphate binding contributes to a destabilization of the VHS domain structure of Tom1. Sci Rep 2019; 9:10868. [PMID: 31350523 PMCID: PMC6659632 DOI: 10.1038/s41598-019-47386-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 03/12/2019] [Accepted: 07/16/2019] [Indexed: 12/21/2022] Open
Abstract
Tom1 transports endosomal ubiquitinated proteins that are targeted for degradation in the lysosomal pathway. Infection of eukaryotic cells by Shigella flexneri boosts oxygen consumption and promotes the synthesis of phosphatidylinositol-5-phosphate (PtdIns5P), which triggers Tom1 translocation to signaling endosomes. Removing Tom1 from its cargo trafficking function hinders protein degradation in the host and, simultaneously, enables bacterial survival. Tom1 preferentially binds PtdIns5P via its VHS domain, but the effects of a reducing environment as well as PtdIns5P on the domain structure and function are unknown. Thermal denaturation studies demonstrate that, under reducing conditions, the monomeric Tom1 VHS domain switches from a three-state to a two-state transition behavior. PtdIns5P reduced thermostability, interhelical contacts, and conformational compaction of Tom1 VHS, suggesting that the phosphoinositide destabilizes the protein domain. Destabilization of Tom1 VHS structure was also observed with other phospholipids. Isothermal calorimetry data analysis indicates that, unlike ubiquitin, Tom1 VHS endothermically binds to PtdIns5P through two noncooperative binding sites, with its acyl chains playing a relevant role in the interaction. Altogether, these findings provide mechanistic insights about the recognition of PtdIns5P by the VHS domain that may explain how Tom1, when in a different VHS domain conformational state, interacts with downstream effectors under S. flexneri infection.
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Affiliation(s)
- Wen Xiong
- Protein Signaling Domains Laboratory, Department of Biological Sciences, Fralin Life Sciences Institute, and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA, 24061, United States
| | - Tuo-Xian Tang
- Protein Signaling Domains Laboratory, Department of Biological Sciences, Fralin Life Sciences Institute, and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA, 24061, United States
| | - Evan Littleton
- Protein Signaling Domains Laboratory, Department of Biological Sciences, Fralin Life Sciences Institute, and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA, 24061, United States
| | - Arba Karcini
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, United States
| | - Iulia M Lazar
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, United States
| | - Daniel G S Capelluto
- Protein Signaling Domains Laboratory, Department of Biological Sciences, Fralin Life Sciences Institute, and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA, 24061, United States.
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3
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Affiliation(s)
- Victoria Dimakos
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
| | - Mark S. Taylor
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
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4
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Affiliation(s)
- Wangze Song
- School of Pharmaceutical Science and Technology, Dalian University of Technology, Dalian, P.R. China
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, P.R. China
| | - Nan Zheng
- Department of Polymer Science and Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian, P.R. China
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, P.R. China
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5
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Gradziel CS, Jordan PA, Jewel D, Dufort FJ, Miller SJ, Chiles TC, Roberts MF. d-3-Deoxy-dioctanoylphosphatidylinositol induces cytotoxicity in human MCF-7 breast cancer cells via a mechanism that involves downregulation of the D-type cyclin-retinoblastoma pathway. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1808-1815. [PMID: 27600289 DOI: 10.1016/j.bbalip.2016.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 08/24/2016] [Accepted: 09/01/2016] [Indexed: 11/29/2022]
Abstract
Phosphatidylinositol analogs (PIAs) were originally designed to bind competitively to the Akt PH domain and prevent membrane translocation and activation. d-3-Deoxy-dioctanoylphosphatidylinositol (d-3-deoxy-diC8PI), but not compounds with altered inositol stereochemistry (e.g., l-3-deoxy-diC8PI and l-3,5-dideoxy-diC8PI), is cytotoxic. However, high resolution NMR field cycling relaxometry shows that both cytotoxic and non-toxic PIAs bind to the Akt1 PH domain at the site occupied by the cytotoxic alkylphospholipid perifosine. This suggests that another mechanism for cytotoxicity must account for the difference in efficacy of the synthetic short-chain PIAs. In MCF-7 breast cancer cells, with little constitutively active Akt, d-3-deoxy-diC8PI (but not l-compounds) decreases viability concomitant with increased cleavage of PARP and caspase 9, indicative of apoptosis. d-3-Deoxy-diC8PI also induces a decrease in endogenous levels of cyclins D1 and D3 and blocks downstream retinoblastoma protein phosphorylation. siRNA-mediated depletion of cyclin D1, but not cyclin D3, reduces MCF-7 cell proliferation. Thus, growth arrest and cytotoxicity induced by the soluble d-3-deoxy-diC8PI occur by a mechanism that involves downregulation of the D-type cyclin-pRb pathway independent of its interaction with Akt. This ability to downregulate D-type cyclins contributes, at least in part, to the anti-proliferative activity of d-3-deoxy-diC8PI and may be a common feature of other cytotoxic phospholipids.
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Affiliation(s)
- Cheryl S Gradziel
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA.
| | - Peter A Jordan
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06520, USA.
| | - Delilah Jewel
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA.
| | - Fay J Dufort
- Department of Biology, Higgins Hall, 140 Commonwealth Avenue, Boston College, Chestnut Hill, MA, USA.
| | - Scott J Miller
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06520, USA.
| | - Thomas C Chiles
- Department of Biology, Higgins Hall, 140 Commonwealth Avenue, Boston College, Chestnut Hill, MA, USA.
| | - Mary F Roberts
- Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467, USA.
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6
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Murray JI, Woscholski R, Spivey AC. Highly efficient and selective phosphorylation of amino acid derivatives and polyols catalysed by 2-aryl-4-(dimethylamino)pyridine-N-oxides--towards kinase-like reactivity. Chem Commun (Camb) 2015; 50:13608-11. [PMID: 25248055 DOI: 10.1039/c4cc05388e] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The chemoselective phosphorylation of hydroxyl containing amino acid derivatives and polyols by phosphoryl chlorides catalyzed by 2-aryl-4-(dimethylamino)pyridine-N-oxides is described.
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Affiliation(s)
- James I Murray
- Department of Chemistry, South Kensington Campus, Imperial College London, SW7 2AZ, UK.
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7
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Wei Y, Stec B, Redfield AG, Weerapana E, Roberts MF. Phospholipid-binding sites of phosphatase and tensin homolog (PTEN): exploring the mechanism of phosphatidylinositol 4,5-bisphosphate activation. J Biol Chem 2014; 290:1592-606. [PMID: 25429968 DOI: 10.1074/jbc.m114.588590] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [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: 11/06/2022] Open
Abstract
The lipid phosphatase activity of the tumor suppressor phosphatase and tensin homolog (PTEN) is enhanced by the presence of its biological product, phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). This enhancement is suggested to occur via the product binding to the N-terminal region of the protein. PTEN effects on short-chain phosphoinositide (31)P linewidths and on the full field dependence of the spin-lattice relaxation rate (measured by high resolution field cycling (31)P NMR using spin-labeled protein) are combined with enzyme kinetics with the same short-chain phospholipids to characterize where PI(4,5)P2 binds on the protein. The results are used to model a discrete site for a PI(4,5)P2 molecule close to, but distinct from, the active site of PTEN. This PI(4,5)P2 site uses Arg-47 and Lys-13 as phosphate ligands, explaining why PTEN R47G and K13E can no longer be activated by that phosphoinositide. Placing a PI(4,5)P2 near the substrate site allows for proper orientation of the enzyme on interfaces and should facilitate processive catalysis.
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Affiliation(s)
- Yang Wei
- From the Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467 and
| | - Boguslaw Stec
- From the Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467 and
| | - Alfred G Redfield
- the Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02454
| | - Eranthie Weerapana
- From the Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467 and
| | - Mary F Roberts
- From the Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467 and
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Vasconcelos MG, Briggs RH, Aguiar LC, Freire DM, Simas AB. Efficient desymmetrization of 4,6-di-O-benzyl-myo-inositol by Lipozyme TL-IM. Carbohydr Res 2014; 386:7-11. [DOI: 10.1016/j.carres.2013.11.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 10/27/2013] [Accepted: 11/11/2013] [Indexed: 10/26/2022]
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Gradziel CS, Wang Y, Stec B, Redfield AG, Roberts MF. Cytotoxic amphiphiles and phosphoinositides bind to two discrete sites on the Akt1 PH domain. Biochemistry 2014; 53:462-72. [PMID: 24383815 DOI: 10.1021/bi401720v] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The mechanism of binding of two promising anticancer agents (the cytotoxic alkylphospholipids perifosine and miltefosine) to the Akt PH domain is investigated by high-resolution field-cycling (31)P nuclear magnetic resonance (NMR) spectroscopy using a spin-labeled recombinant PH domain. These results strongly indicate that there are two discrete amphiphile binding sites on the domain: (i) the cationic site that binds phosphoinositides and some alkylphospholipids and (ii) a second site that is occupied by only the alkylphospholipids. The identification of this second site for amphiphiles on the Akt1 PH domain provides a new target for drug development as well as insights into the regulation of the activity of the intact Akt1 protein. The field-cycling NMR methodology could be used to define discrete phospholipid or amphiphile binding sites on a wide variety of peripheral membrane proteins.
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Affiliation(s)
- Cheryl S Gradziel
- Department of Chemistry, Boston College , Chestnut Hill, Massachusetts 02467, United States
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10
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Chandler BD, Burkhardt AL, Foley K, Cullis C, Driscoll D, Roy D'Amore N, Miller SJ. A fully synthetic and biochemically validated phosphatidyl inositol-3-phosphate hapten via asymmetric synthesis and native chemical ligation. J Am Chem Soc 2013; 136:412-8. [PMID: 24344932 DOI: 10.1021/ja410750a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the synthesis and biochemical validation of a phosphatidyl inositol-3 phosphate (PI3P) immunogen. The inositol stereochemistry was secured through peptide-catalyzed asymmetric phosphorylation catalysis, and the subsequent incorporation of a cysteine residue was achieved by native chemical ligation (NCL). Conjugation of the PI3P hapten to maleimide-activated keyhole limpet hemocyanin (KLH) provided a PI3P immunogen, which was successfully used to generate selective PI3P antibodies. The incorporation of a sulfhydryl nucleophile into a phosphoinositide hapten demonstrates a general strategy to reliably access phosphoinositide immunogens.
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Affiliation(s)
- Brent D Chandler
- Department of Chemistry, Yale University , P.O. Box 208107, United States
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11
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Abstract
Phosphatidylinositol-4,5-bisphosphate (PIP2), which constitutes ∼1% of the plasma membrane phospholipid, plays a key role in membrane-delimited signaling. PIP2 regulates structurally and functionally diverse membrane proteins, including voltage- and ligand-gated ion channels, inwardly rectifying ion channels, transporters, and receptors. In some cases, the regulation is known to involve specific lipid–protein interactions, but the mechanisms by which PIP2 regulates many of its various targets remain to be fully elucidated. Because many PIP2 targets are membrane-spanning proteins, we explored whether the phosphoinositides might alter bilayer physical properties such as curvature and elasticity, which would alter the equilibrium between membrane protein conformational states—and thereby protein function. Taking advantage of the gramicidin A (gA) channels’ sensitivity to changes in lipid bilayer properties, we used gA-based fluorescence quenching and single-channel assays to examine the effects of long-chain PIP2s (brain PIP2, which is predominantly 1-stearyl-2-arachidonyl-PIP2, and dioleoyl-PIP2) on bilayer properties. When premixed with dioleoyl-phosphocholine at 2 mol %, both long-chain PIP2s produced similar changes in gA channel function (bilayer properties); when applied through the aqueous solution, however, brain PIP2 was a more potent modifier than dioleoyl-PIP2. Given the widespread use of short-chain dioctanoyl-phosphoinositides, we also examined the effects of diC8-phosphoinositol (PI), PI(4,5)P2, PI(3,5)P2, PI(3,4)P2, and PI(3,4,5)P3. The diC8 phosphoinositides, except for PI(3,5)P2, altered bilayer properties with potencies that decreased with increasing head group charge. Nonphosphoinositide diC8 phospholipids generally were more potent bilayer modifiers than the polyphosphoinositides. These results show that physiological increases or decreases in plasma membrane PIP2 levels, as a result of activation of PI kinases or phosphatases, are likely to alter lipid bilayer properties, in addition to any other effects they may have. The results further show that exogenous PIP2, as well as structural analogues that differ in acyl chain length or phosphorylation state, alters lipid bilayer properties at the concentrations used in many cell physiological experiments.
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Affiliation(s)
- Radda Rusinova
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10065, USA.
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12
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Kore AR, Xiao Z, Li M. Synthesis and biological validation of N⁷-(4-chlorophenoxyethyl) substituted dinucleotide cap analogs for mRNA translation. Bioorg Med Chem 2013; 21:4570-4. [PMID: 23777824 DOI: 10.1016/j.bmc.2013.05.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 05/08/2013] [Accepted: 05/17/2013] [Indexed: 11/20/2022]
Abstract
Design, synthesis and biological validation of dinucleotide cap analogs, N(7)-(4-chlorophenoxyethyl)-G(5')ppp(5')G (5a) and N(7)-(4-chlorophenoxyethyl)-m(3'-O)G(5')ppp(5')G (5b) are reported. The effect of N(7)-(4-chlorophenoxyethyl) substitution on cap analogs has been evaluated with respect to its in vitro transcription by using T7 RNA polymerase capping efficiency, and translational activity. The gel shift assay indicates that the new cap analogs (5a, 5b) showed 77% and 76% capping efficiency respectively, whereas the standard cap analog, m(7)G(5')ppp(5')G has a capping efficiency of 63%. The capping efficiency experiment clearly demonstrates that the N(7)-modified analogs are good substrate for T7 RNA polymerase. It is noteworthy that the mRNA poly(A) capped with N(7)-(4-chlorophenoxyethyl)-m(3'-O)G(5')ppp(5')G (5b) was translated ∼1.64-fold more efficiently, while compound (5a) was translated ∼0.72-fold less efficiently than mRNA capped with standard cap analog. The observed low translation activity for (5a) could be due to stability in the form of dinucleotide cap analogs. Based on the substrate compatability of the N(7) modification in dinucleotide form, these new analogs may be used for structure function studies as well as protein production.
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13
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Dimitrijević E, Taylor MS. 9-Hetero-10-boraanthracene-derived borinic acid catalysts for regioselective activation of polyols. Chem Sci 2013. [DOI: 10.1039/c3sc51172c] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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14
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Zhong S, Hsu F, Stefan CJ, Wu X, Patel A, Cosgrove MS, Mao Y. Allosteric activation of the phosphoinositide phosphatase Sac1 by anionic phospholipids. Biochemistry 2012; 51:3170-7. [PMID: 22452743 PMCID: PMC3329130 DOI: 10.1021/bi300086c] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [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: 01/14/2023]
Abstract
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Sac family phosphoinositide phosphatases comprise an evolutionarily conserved family of enzymes in eukaryotes. Our recently determined crystal structure of the Sac phosphatase domain of yeast Sac1, the founding member of the Sac family proteins, revealed a unique conformation of the catalytic P-loop and a large positively charged groove at the catalytic site. We now report a unique mechanism for the regulation of its phosphatase activity. Sac1 is an allosteric enzyme that can be activated by its product phosphatidylinositol or anionic phospholipid phosphatidylserine. The activation of Sac1 may involve conformational changes of the catalytic P-loop induced by direct binding with the regulatory anionic phospholipids in the large cationic catalytic groove. These findings highlight the fact that lipid composition of the substrate membrane plays an important role in the control of Sac1 function.
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Affiliation(s)
- Shurong Zhong
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, United States
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15
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Redfield AG. High-resolution NMR field-cycling device for full-range relaxation and structural studies of biopolymers on a shared commercial instrument. J Biomol NMR 2012; 52:159-177. [PMID: 22200887 DOI: 10.1007/s10858-011-9594-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Accepted: 12/05/2011] [Indexed: 05/31/2023]
Abstract
Improvements are described in a shuttling field-cycling device (Redfield in Magn Reson Chem 41:753-768, 2003), designed to allow widespread access to this useful technique by configuring it as a removable module to a commercial 500 MHz NMR instrument. The main improvements described here, leading to greater versatility, high reliability and simple construction, include: shuttling provided by a linear motor driven by an integrated-control servomotor; provision of automated bucking magnets to allow fast two-stage cycling to nearly zero field; and overall control by a microprocessor. A brief review of history and publications that have used the system is followed by a discussion of topics related to such a device including discussion of some future applications. A description of new aspects of the shuttling device follows. The minimum round trip time to 1T and above is less than 0.25 s and to 0.002 T is 0.36 s. Commercial probes are used and sensitivity is that of the host spectrometer reduced only by relaxation during travel. A key element is development of a linkage that prevents vibration of the linear motor from reaching the probe.
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Affiliation(s)
- Alfred G Redfield
- Biochemistry Department, Brandeis University, Mail stop 009, Waltham, MA 02154, USA.
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Patil PS, Hung SC. Synthesis of mycobacterial triacylated phosphatidylinositol dimannoside containing an acyl lipid chain at 3-O of inositol. Org Lett 2010; 12:2618-21. [PMID: 20443632 DOI: 10.1021/ol1008137] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A seven-step synthesis of triacylated phosphatidylinositol dimannoside is described from myo-inositol 1,3,5-orthoformate. It proceeded in 31% overall yield via a highly regioselective and stereoselective 2,6-di-O-D-mannosylation as the key step.
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Affiliation(s)
- Pratap S Patil
- Genomics Research Center, Academia Sinica, 128, Section 2, Academia Road, Taipei 11529, Taiwan
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18
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Wang Q, Wei Y, Mottamal M, Roberts MF, Krilov G. Understanding the stereospecific interactions of 3-deoxyphosphatidylinositol derivatives with the PTEN phosphatase domain. J Mol Graph Model 2010; 29:102-14. [PMID: 20538496 DOI: 10.1016/j.jmgm.2010.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [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: 03/12/2010] [Accepted: 05/07/2010] [Indexed: 11/20/2022]
Abstract
PTEN is an important control element of PI3K/AKT signaling involved in controlling the processes of embryonic development, cell migration and apoptosis. While its dysfunction is implicated in a large fraction of cancers, PTEN activity in the same pathway may also contribute to metabolic syndromes such as diabetes. In those cases, selective inhibitors of PTEN may be useful. A new class of chiral PTEN inhibitors based on the 3-deoxy-phosphatidylinositol derivatives was recently identified (Wang et al. [17]). However, lack of detailed understanding of protein-ligand interactions has hampered efforts to develop effective agonists or antagonists of PTEN. Here, we use computational modeling to characterize the interactions of the diverse 3-deoxyphosphatidylinositol inhibitors with the PTEN protein. We show that, while each of the compounds binds with the inositol headgroup inserting into the proposed active site of the PTEN phosphatase domain, hydrogen bonding restrictions lead to distinct binding geometries for ligand pairs of opposite chirality. We furthermore demonstrate that the binding modes differ primarily in the orientation of acyl tails of the ligands and that the activity of the compounds is primarily controlled by the effectiveness of tail-protein contacts. These findings are confirmed by binding affinity calculations which are in good agreement with experiment. Finally, we show that while more potent d-series ligands bind in a manner similar to that of the native substrate, an alternate hydrophobic pocket suitable for binding the opposite chirality l-series inhibitors exists, offering the possibility of designing highly selective PTEN-targeting compounds.
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Affiliation(s)
- Qin Wang
- Department of Chemistry, Boston College, Merkert Chemistry Center, Chestnut Hill, MA 02467, USA
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19
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Jordan PA, Kayser-Bricker KJ, Miller SJ. Asymmetric phosphorylation through catalytic P(III) phosphoramidite transfer: enantioselective synthesis of D-myo-inositol-6-phosphate. Proc Natl Acad Sci U S A 2010; 107:20620-4. [PMID: 20439750 DOI: 10.1073/pnas.1001111107] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite the ubiquitous use of phosphoramidite chemistry in the synthesis of biophosphates, catalytic asymmetric phosphoramidite transfer remains largely unexplored for phosphate ester synthesis. We have discovered that a tetrazole-functionalized peptide, in the presence of 10-Å molecular sieves, functions as an enantioselective catalyst for phosphite transfer. This chemistry in turn has been used as the key step in a streamlined synthesis of myo-inositol-6-phosphate. Mechanistic insights implicate phosphate as a directing group for a highly selective kinetic resolution of a protected inositol monophosphate. This work represents a distinct and efficient method for the selective catalytic phosphorylation of natural products.
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Best MD, Zhang H, Prestwich GD. Inositol polyphosphates, diphosphoinositol polyphosphates and phosphatidylinositol polyphosphate lipids: Structure, synthesis, and development of probes for studying biological activity. Nat Prod Rep 2010; 27:1403-30. [DOI: 10.1039/b923844c] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Devaraj S, Jagdhane RC, Shashidhar MS. Relative reactivity of hydroxyl groups in inositol derivatives: role of metal ion chelation. Carbohydr Res 2009; 344:1159-66. [DOI: 10.1016/j.carres.2009.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 04/04/2009] [Accepted: 04/09/2009] [Indexed: 10/20/2022]
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Keddie NS, Bultynck G, Luyten T, Slawin AM, Conway SJ. A type 2 Ferrier rearrangement-based synthesis of d-myo-inositol 1,4,5-trisphosphate. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.tetasy.2009.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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