1
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Shi B, Zhou X, He L, Liang M, Luo Y, Jiang P. Reduced RCE1 expression predicts poor prognosis of colorectal carcinoma. BMC Cancer 2017; 17:414. [PMID: 28615075 PMCID: PMC5471898 DOI: 10.1186/s12885-017-3393-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 05/26/2017] [Indexed: 12/30/2022] Open
Abstract
Background As an end-proteolytic enzyme that cleaves the last three residues of proteins with a terminal CAAX, Ras-converting enzyme 1 (RCE1) has an essential role in multiple signaling pathways and take part in the process of differentiation, proliferation and carcinogenesis. The aim of the study is to investigate expression pattern of RCE1 and its prognosis in colorectal carcinoma (CRC). Methods The expression of RCE1 and phospho-MAPK family members was confirmed by immunohistochemical staining of CRC tissues. miR-RCE1 lentiviral vectors were transduced into HCT116 and SW489 cells. Reverse transcription PCR (RT-PCR) and western blot were conducted to measure the transfection efficiency. Transwell assays were used to detect the invasiveness of CRC cells. Results In the present study, we assessed RCE1 expression in 244 CRC specimens and matching adjacent, non-tumorous tissues by immunohistochemistry (IHC). Compared with the matched adjacent non-tumor tissue samples, the RCE1 reduced in the tumor tissue samples (p < 0.001). RCE1 expression was significantly decreased in 106 of 244 (43.4%) CRC cases. In univariate and multivariate analyses, Decreasing expression of RCE1 independently predicts poor prognosis for patients in both overall survival and disease-free survival. Further study indicated that RCE1 influenced tumor invasion through the p38 pathway. Knockdown of RCE1 reduced phosphorylation and significantly increased the invasive capacity of CRC cells. Conclusion Taken together, the outcomes of this study indicate that RCE1 acts as a tumor suppressor in CRC, as its reduced expression may increase CRC cell invasion and independently predict an unsatisfactory prognosis in CRC patients. Electronic supplementary material The online version of this article (doi:10.1186/s12885-017-3393-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Boyun Shi
- Department of Oncology, The Fifth Affiliated Hospital, Guangzhou Medical University, 621 Harbor Road, Guangzhou, Guangdong, 510700, China
| | - Xinke Zhou
- Department of Oncology, The Fifth Affiliated Hospital, Guangzhou Medical University, 621 Harbor Road, Guangzhou, Guangdong, 510700, China.
| | - Lu He
- Department of Radiotherapy, Affiliated Tumour Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Min Liang
- Department of Oncology, The Fifth Affiliated Hospital, Guangzhou Medical University, 621 Harbor Road, Guangzhou, Guangdong, 510700, China
| | - Yuanwei Luo
- Department of Oncology, The Fifth Affiliated Hospital, Guangzhou Medical University, 621 Harbor Road, Guangzhou, Guangdong, 510700, China
| | - Peng Jiang
- Department of Radiotherapy, Affiliated Tumour Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
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2
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Palsuledesai CC, Distefano MD. Protein prenylation: enzymes, therapeutics, and biotechnology applications. ACS Chem Biol 2015; 10:51-62. [PMID: 25402849 PMCID: PMC4301080 DOI: 10.1021/cb500791f] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
Protein
prenylation is a ubiquitous covalent post-translational modification
found in all eukaryotic cells, comprising attachment of either a farnesyl
or a geranylgeranyl isoprenoid. It is essential for the proper cellular
activity of numerous proteins, including Ras family GTPases and heterotrimeric
G-proteins. Inhibition of prenylation has been extensively investigated
to suppress the activity of oncogenic Ras proteins to achieve antitumor
activity. Here, we review the biochemistry of the prenyltransferase
enzymes and numerous isoprenoid analogs synthesized to investigate
various aspects of prenylation and prenyltransferases. We also give
an account of the current status of prenyltransferase inhibitors as
potential therapeutics against several diseases including cancers,
progeria, aging, parasitic diseases, and bacterial and viral infections.
Finally, we discuss recent progress in utilizing protein prenylation
for site-specific protein labeling for various biotechnology applications.
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Affiliation(s)
- Charuta C. Palsuledesai
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Mark D. Distefano
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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3
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Subramanian T, Ren H, Subramanian KL, Sunkara M, Onono FO, Morris AJ, Spielmann HP. Design and synthesis of non-hydrolyzable homoisoprenoid α-monofluorophosphonate inhibitors of PPAPDC family integral membrane lipid phosphatases. Bioorg Med Chem Lett 2014; 24:4414-4417. [PMID: 25150376 DOI: 10.1016/j.bmcl.2014.08.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/01/2014] [Accepted: 08/05/2014] [Indexed: 12/20/2022]
Abstract
An efficient, diversity oriented synthesis of homoisoprenoid α-monofluorophosphonates utilizing electrophilic fluorination is presented along with their activity as inhibitors of PPAPDC2 family integral membrane lipid phosphatases. These novel phosphatase-resistant analogues of isoprenoid monophosphates are a platform for further structure-activity relationship studies and provide access to other isoprenoid family members where the phosphate ester oxygen is replaced by a α-monofluoromethylene moiety.
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Affiliation(s)
- Thangaiah Subramanian
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Hongmei Ren
- Division of Cardiovascular Medicine UK COM, University of Kentucky, Lexington, KY 40536, USA
| | | | - Manjula Sunkara
- Division of Cardiovascular Medicine UK COM, University of Kentucky, Lexington, KY 40536, USA
| | - Fredrick O Onono
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Andrew J Morris
- Division of Cardiovascular Medicine UK COM, University of Kentucky, Lexington, KY 40536, USA; Lexington Veterans Affairs Medical Center, University of Kentucky, Lexington, KY 40536, USA
| | - H Peter Spielmann
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA; Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA; Kentucky Center for Structural Biology, University of Kentucky, Lexington, KY 40536, USA; Department of Chemistry, University of Kentucky, Lexington, KY 40536, USA.
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4
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Srinivasan K, Subramanian T, Spielmann HP, Janetopoulos C. Identification of a farnesol analog as a Ras function inhibitor using both an in vivo Ras activation sensor and a phenotypic screening approach. Mol Cell Biochem 2013; 387:177-86. [PMID: 24194124 DOI: 10.1007/s11010-013-1883-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 10/26/2013] [Indexed: 10/26/2022]
Abstract
Mutations in Ras isoforms such as K-Ras, N-Ras, and H-Ras contribute to roughly 85, 15, and 1% of human cancers, respectively. Proper membrane targeting of these Ras isoforms, a prerequisite for Ras activity, requires farnesylation or geranylgeranylation at the C-terminal CAAX box. We devised an in vivo screening strategy based on monitoring Ras activation and phenotypic physiological outputs for assaying synthetic Ras function inhibitors (RFI). Ras activity was visualized by the translocation of RBD Raf1 -GFP to activated Ras at the plasma membrane. By using this strategy, we screened one synthetic farnesyl substrate analog (AGOH) along with nine putative inhibitors and found that only m-CN-AGOH inhibited Ras activation. Phenotypic analysis of starving cells could be used to monitor polarization, motility, and the inability of these treated cells to aggregate properly during fruiting body formation. Incorporation of AGOH and m-CN-AGOH to cellular proteins was detected by western blot. These screening assays can be incorporated into a high throughput screening format using Dictyostelium discoideum and automated microscopy to determine effective RFIs. These RFI candidates can then be further tested in mammalian systems.
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5
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Subramanian T, Pais JE, Liu S, Troutman JM, Suzuki Y, Leela Subramanian K, Fierke CA, Andres DA, Spielmann HP. Farnesyl diphosphate analogues with aryl moieties are efficient alternate substrates for protein farnesyltransferase. Biochemistry 2012; 51:8307-19. [PMID: 22989235 DOI: 10.1021/bi3011362] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Farnesylation is an important post-translational modification essential for the proper localization and function of many proteins. Transfer of the farnesyl group from farnesyl diphosphate (FPP) to proteins is catalyzed by protein farnesyltransferase (FTase). We employed a library of FPP analogues with a range of aryl groups substituting for individual isoprene moieties to examine some of the structural and electronic properties of the transfer of an analogue to the peptide catalyzed by FTase. Analysis of steady-state kinetics for modification of peptide substrates revealed that the multiple-turnover activity depends on the analogue structure. Analogues in which the first isoprene is replaced with a benzyl group and an analogue in which each isoprene is replaced with an aryl group are good substrates. In sharp contrast with the steady-state reaction, the single-turnover rate constant for dansyl-GCVLS alkylation was found to be the same for all analogues, despite the increased chemical reactivity of the benzyl analogues and the increased steric bulk of other analogues. However, the single-turnover rate constant for alkylation does depend on the Ca(1)a(2)X peptide sequence. These results suggest that the isoprenoid transition-state conformation is preferred over the inactive E·FPP·Ca(1)a(2)X ternary complex conformation. Furthermore, these data suggest that the farnesyl binding site in the exit groove may be significantly more selective for the farnesyl diphosphate substrate than the active site binding pocket and therefore might be a useful site for the design of novel inhibitors.
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Affiliation(s)
- Thangaiah Subramanian
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536-0084, USA
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6
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Subramanian T, Parkin S, Spielmann HP. Synthesis of Farnesol Analogues Containing Triazoles in Place of Isoprenes through 'Click Chemistry'. Synlett 2012; 23:2539-2543. [PMID: 23125482 DOI: 10.1055/s-0031-1290461] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A solid-phase three-component Huisgen reaction has been used to generate polar farnesol and farnesyl diphosphate analogues. The Cu(I)-catalyzed 1,3-cycloadditions of various azides with solid supported (E)-3-methylhept-2-en-6-yn-1-ol provided only the 1,4-disubstituted 1,2,3-triazole regioisomers. The organic azides were generated in situ to minimize handling of potentially explosive azides. We have employed this powerful 'click chemistry' to make farnesol analogues where both β- and γ-isoprenes were replaced by triazole and substituted aromatic rings, respectively.
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Affiliation(s)
- Thangaiah Subramanian
- Department of Cellular and Molecular Biochemistry, University of Kentucky, Lexington, KY, 40536, USA
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7
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Lujan DK, Stanziale JA, Mostafavi AZ, Sharma S, Troutman JM. Chemoenzymatic synthesis of an isoprenoid phosphate tool for the analysis of complex bacterial oligosaccharide biosynthesis. Carbohydr Res 2012; 359:44-53. [PMID: 22925763 DOI: 10.1016/j.carres.2012.06.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 06/22/2012] [Accepted: 06/23/2012] [Indexed: 10/28/2022]
Abstract
Undecaprenyl Pyrophosphate Synthase (UPPS) is a key enzyme that catalyzes the production of bactoprenols, which act as membrane anchors for the assembly of complex bacterial oligosaccharides. One of the major hurdles in understanding the assembly of oligosaccharide assembly is a lack of chemical tools to study this process, since bactoprenols and the resulting isoprenoid-linked oligosaccharides lack handles or chromophores for use in pathway analysis. Here we describe the isolation of a new UPPS from the symbiotic microorganism Bacteroides fragilis, a key species in the human microbiome. The protein was purified to homogeneity and utilized to accept a chromophore containing farnesyl diphosphate analogue as a substrate. The analogue was utilized by the enzyme and resulted in a bactoprenyl diphosphate product with an easy to monitor tag associated with it. Furthermore, the diphosphate is shown to be readily converted to monophosphate using a common molecular biology reagent. This monophosphate product allowed for the investigation of complex oligosaccharide biosynthesis, and was used to probe the activity of glycosyltransferases involved in the well characterized Campylobacter jejuni N-linked protein glycosylation. Novel reagents similar to this will provide key tools for the study of uncharacterized oligosaccharide assemblies, and open the possibility for the development of rapid screening methodology for these biosynthetic systems.
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Affiliation(s)
- Donovan K Lujan
- Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, United States
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8
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Bergman JA, Hahne K, Song J, Hrycyna CA, Gibbs RA. S-Farnesyl-Thiopropionic Acid (FTPA) Triazoles as Potent Inhibitors of Isoprenylcysteine Carboxyl Methyltransferase. ACS Med Chem Lett 2012; 3:15-19. [PMID: 22754607 DOI: 10.1021/ml200106d] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We report the design and synthesis of novel FTPA-triazole compounds as potent inhibitors of isoprenylcysteine carboxyl methyltransferase (Icmt), through a focus on thioether and isoprenoid mimetics. These mimetics were coupled utilizing a copper-assisted cycloaddition to assemble the potential inhibitors. Using the resulting triazole from the coupling as an isoprenyl mimetic resulted in the biphenyl substituted FTPA triazole 10n. This lipid-modified analog is a potent inhibitor of Icmt (IC(50) = 0.8 ± 0.1 μM; calculated K(i) = 0.4 μM).
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Affiliation(s)
- Joel A. Bergman
- Department
of Medicinal Chemistry and Molecular Pharmacology and the Center for
Cancer Research, and ‡Department of Chemistry and the Center for Cancer Research, Purdue University, West Lafayette, Indiana
47907, United States
| | - Kalub Hahne
- Department
of Medicinal Chemistry and Molecular Pharmacology and the Center for
Cancer Research, and ‡Department of Chemistry and the Center for Cancer Research, Purdue University, West Lafayette, Indiana
47907, United States
| | - Jiao Song
- Department
of Medicinal Chemistry and Molecular Pharmacology and the Center for
Cancer Research, and ‡Department of Chemistry and the Center for Cancer Research, Purdue University, West Lafayette, Indiana
47907, United States
| | - Christine A. Hrycyna
- Department
of Medicinal Chemistry and Molecular Pharmacology and the Center for
Cancer Research, and ‡Department of Chemistry and the Center for Cancer Research, Purdue University, West Lafayette, Indiana
47907, United States
| | - Richard A. Gibbs
- Department
of Medicinal Chemistry and Molecular Pharmacology and the Center for
Cancer Research, and ‡Department of Chemistry and the Center for Cancer Research, Purdue University, West Lafayette, Indiana
47907, United States
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9
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Kyro K, Manandhar SP, Mullen D, Schmidt WK, Distefano MD. Photoaffinity labeling of Ras converting enzyme using peptide substrates that incorporate benzoylphenylalanine (Bpa) residues: improved labeling and structural implications. Bioorg Med Chem 2011; 19:7559-69. [PMID: 22079863 DOI: 10.1016/j.bmc.2011.10.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/04/2011] [Accepted: 10/10/2011] [Indexed: 11/17/2022]
Abstract
Rce1p catalyzes the proteolytic trimming of C-terminal tripeptides from isoprenylated proteins containing CAAX-box sequences. Because Rce1p processing is a necessary component in the Ras pathway of oncogenic signal transduction, Rce1p holds promise as a potential target for therapeutic intervention. However, its mechanism of proteolysis and active site have yet to be defined. Here, we describe synthetic peptide analogues that mimic the natural lipidated Rce1p substrate and incorporate photolabile groups for photoaffinity-labeling applications. These photoactive peptides are designed to crosslink to residues in or near the Rce1p active site. By incorporating the photoactive group via p-benzoyl-l-phenylalanine (Bpa) residues directly into the peptide substrate sequence, the labeling efficiency was substantially increased relative to a previously-synthesized compound. Incorporation of biotin on the N-terminus of the peptides permitted photolabeled Rce1p to be isolated via streptavidin affinity capture. Our findings further suggest that residues outside the CAAX-box sequence are in contact with Rce1p, which has implications for future inhibitor design.
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Affiliation(s)
- Kelly Kyro
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
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10
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Placzek AT, Krzysiak AJ, Gibbs RA. Chemical Probes of Protein Prenylation. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/b978-0-12-415922-8.00005-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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11
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Kyro K, Manandhar SP, Mullen D, Schmidt WK, Distefano MD. Photoaffinity labeling of Ras converting enzyme 1 (Rce1p) using a benzophenone-containing peptide substrate. Bioorg Med Chem 2010; 18:5675-84. [PMID: 20619662 DOI: 10.1016/j.bmc.2010.06.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 06/04/2010] [Accepted: 06/07/2010] [Indexed: 11/30/2022]
Abstract
Isoprenylation is a post-translational modification that increases protein hydrophobicity and helps target certain proteins to membranes. Ras converting enzyme 1 (Rce1p) is an endoprotease that catalyzes the removal of a three residue fragment from the C-terminus of isoprenylated proteins. To obtain structural information about this membrane protein, photoaffinity labeling agents are being prepared and employed. Here, we describe the synthesis of a benzophenone-containing peptide substrate analogue for Rce1p. Using a continuous spectrofluorometric assay, this peptide was shown to be a substrate for Rce1p. Mass spectrometry was performed to confirm the site of cleavage and structure of the processed probe. Photolysis of the biotinylated compound in the presence of membranes containing Rce1p followed by streptavidin pull-down and Western blot analysis indicated that Rce1p had been labeled by the probe. Photolysis in the presence of both the biotinylated, benzophenone-containing probe and a farnesylated peptide competitor reduced the extent of labeling, suggesting that labeling is occurring in the active site.
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Affiliation(s)
- Kelly Kyro
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
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12
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Wollack JW, Zeliadt NA, Ochocki JD, Mullen DG, Barany G, Wattenberg EV, Distefano MD. Investigation of the sequence and length dependence for cell-penetrating prenylated peptides. Bioorg Med Chem Lett 2009; 20:161-3. [PMID: 20004573 DOI: 10.1016/j.bmcl.2009.11.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 11/02/2009] [Accepted: 11/05/2009] [Indexed: 10/20/2022]
Abstract
Cell penetrating peptides are useful delivery tools for introducing molecules of interest into cells. A new class of cell penetrating molecules has been recently reported-cell penetrating, prenylated peptides. In this study a series of such peptides was synthesized to examine the relationship between peptide sequence and level of peptide internalization and to probe their mechanism of internalization. This study revealed that prenylated peptides internalize via a non-endocytotic pathway regardless of sequence. Sequence length and identity was found to play a role in peptide uptake but prenylated sequences as short as two amino acids were found to exhibit significant cell penetrating properties.
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Affiliation(s)
- James W Wollack
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
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13
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Wollack JW, Zeliadt NA, Mullen DG, Amundson G, Geier S, Falkum S, Wattenberg EV, Barany G, Distefano MD. Multifunctional prenylated peptides for live cell analysis. J Am Chem Soc 2009; 131:7293-303. [PMID: 19425596 DOI: 10.1021/ja805174z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Protein prenylation is a common post-translational modification present in eukaryotic cells. Many key proteins involved in signal transduction pathways are prenylated, and inhibition of prenylation can be useful as a therapeutic intervention. While significant progress has been made in understanding protein prenylation in vitro, we have been interested in studying this process in living cells, including the question of where prenylated molecules localize. Here, we describe the synthesis and live cell analysis of a series of fluorescently labeled multifunctional peptides, based on the C-terminus of the naturally prenylated protein CDC42. A synthetic route was developed that features a key Acm to Scm protecting group conversion. This strategy was compatible with acid-sensitive isoprenoid moieties and allowed incorporation of an appropriate fluorophore as well as a cell-penetrating sequence (penetratin). These peptides are able to enter cells through different mechanisms, depending on the presence or absence of the penetratin vehicle and the nature of the prenyl group attached. Interestingly, prenylated peptides lacking penetratin are able to enter cells freely through an energy-independent process and localize in a perinuclear fashion. This effect extends to a prenylated peptide that includes a full "CAAX box" sequence (specifically, CVLL). Hence, these peptides open the door for studies of protein prenylation in living cells, including enzymatic processing and intracellular peptide trafficking. Moreover, the synthetic strategy developed here should be useful for the assembly of other types of peptides that contain acid-sensitive functionalities.
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Affiliation(s)
- James W Wollack
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA
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14
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Subramanian T, Liu S, Troutman JM, Andres DA, Spielmann HP. Protein farnesyltransferase-catalyzed isoprenoid transfer to peptide depends on lipid size and shape, not hydrophobicity. Chembiochem 2009; 9:2872-82. [PMID: 18985644 DOI: 10.1002/cbic.200800248] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Protein farnesyl transferase (FTase) catalyzes transfer of a 15-carbon farnesyl group from farnesyl diphosphate (FPP) to a conserved cysteine in the C-terminal Ca(1)a(2)X motif of a range of proteins, including the oncoprotein H-Ras ("C" refers to the cysteine, "a" to any aliphatic amino acid, and "X" to any amino acid) and the lipid chain interacts with, and forms part of the Ca(1)a(2)X peptide binding site. Previous studies have shown that H-Ras biological function is ablated when it is modified with lipids that are 3-5 orders of magnitude less hydrophobic than FPP. Here, we employed a library of anilinogeranyl diphosphate (AGPP) and phenoxygeranyl diphosphate (PGPP) derivatives with a range of polarities (log P (lipid alcohol) = 0.7-6.8, log P (farnesol) = 6.1) and shapes to examine whether FTase-catalyzed transfer to peptide is dependent on the hydrophobicity of the lipid. Analysis of steady-state transfer kinetics for analogues to dansyl-GCVLS peptide revealed that the efficiency of lipid transfer was highly dependent on both the shape and size, but was independent of the polarity of the analogue. These observations indicate that hydrophobic features of isoprenoids critical for their association with membranes and/or protein receptors are not required for efficient transfer to Ca(1)a(2)X peptides by FTase. Furthermore, the results of these studies indicate that the role played by the farnesyl lipid in the FTase mechanism is primarily structural. To explain these results we propose a model in which the FTase active site stabilizes a membrane interface-like environment.
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Affiliation(s)
- Thangaiah Subramanian
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky 40536-0084, USA
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15
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Konstantinopoulos PA, Karamouzis MV, Papavassiliou AG. Post-translational modifications and regulation of the RAS superfamily of GTPases as anticancer targets. Nat Rev Drug Discov 2007; 6:541-55. [PMID: 17585331 DOI: 10.1038/nrd2221] [Citation(s) in RCA: 355] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The involvement of the RAS superfamily of monomeric GTPases in carcinogenesis is increasingly being appreciated. A complex array of post-translational modifications and a highly sophisticated protein network regulate the spatio-temporal activation of these GTPases. Previous attempts to pharmacologically target this family have focused on the development of farnesyltransferase inhibitors, but the performance of such agents in cancer clinical trials has not been as good as hoped. Here, we review emerging druggable targets and novel therapeutic approaches targeting prenylation and post-prenylation modifications and the functional regulation of GDP/GTP exchange as exciting alternatives for anticancer therapy.
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16
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Krzysiak AJ, Rawat DS, Scott SA, Pais JE, Handley M, Harrison ML, Fierke CA, Gibbs RA. Combinatorial modulation of protein prenylation. ACS Chem Biol 2007; 2:385-9. [PMID: 17530735 PMCID: PMC2922964 DOI: 10.1021/cb700062b] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The cell has >60 different farnesylated proteins. Many critically important signal transduction proteins are post-translationally modified with attachment of a farnesyl isoprenoid catalyzed by protein farnesyltransferase (FTase). Recently, it has been shown that farnesyl diphosphate (FPP) analogues can alter the peptide substrate specificity of FTase. We have used combinatorial screening of FPP analogues and peptide substrates to identify patterns in FTase substrate selectivity. Each FPP analogue displays a unique pattern of substrate reactivity with the tested peptides; FTase efficiently catalyzes the transfer of an FPP analogue selectively to one peptide and not another. Furthermore, we have demonstrated that these analogues can enter cells and be incorporated into proteins. These FPP analogues could serve as selective tools to examine the role prenylation plays in individual protein function.
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Affiliation(s)
- Amanda J. Krzysiak
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47907
| | | | - Sarah A. Scott
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47907
| | - June E. Pais
- Departments of Chemistry and Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109
| | - Misty Handley
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47907
| | - Marietta L. Harrison
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47907
| | - Carol A. Fierke
- Departments of Chemistry and Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109
| | - Richard A. Gibbs
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47907
- Corresponding author,
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