1
|
Khan N, Park J, Dean WL, Gray RD, Tse W, Lee D, Sabo TM. Recombinant expression and purification of AF1q and its interaction with T-cell Factor 7. Protein Expr Purif 2019; 165:105499. [PMID: 31541685 DOI: 10.1016/j.pep.2019.105499] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/12/2019] [Accepted: 09/17/2019] [Indexed: 11/17/2022]
Abstract
The protein ALL1 fused from chromosome 1q (AF1q) is overexpressed in a variety of cancers and acts to activate several signaling pathways that lead to oncogenesis. For example, AF1q has been shown to interact with T-cell Factor 7 (TCF7; also known as TCF1) from the Wnt/β-catenin pathway resulting in the transcriptional activation of the CD44 and the enhancement of breast cancer metastasis. Despite the importance of AF1q in facilitating oncogenesis and metastasis, the structural and biophysical properties of AF1q remain largely unexplored due to the absence of a viable method for producing recombinant protein. Here, we report the overexpression of AF1q in E. coli as a fusion to a N-terminal His6-tag, which forms inclusion bodies (IBs) during expression. The AF1q protein was purified from IBs under denaturing conditions by immobilized metal affinity chromatography followed by a successful one-step dialysis refolding. Refolded AF1q was further purified to homogeneity by gel filtration chromatography resulting in an overall yield of 35 mg/L culture. Our nuclear magnetic resonance (NMR) and analytical ultracentrifugation (AUC) measurements reveal AF1q interacts with TCF7, specifically with TCF7's high-mobility group (HMG) domain (residues 154-237), which is, to our knowledge, the first biophysical characterization of the AF1q and TCF7 interaction.
Collapse
Affiliation(s)
- Nazimuddin Khan
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY, 40202, USA
| | - Jino Park
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY, 40202, USA
| | - William L Dean
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY, 40202, USA
| | - Robert D Gray
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY, 40202, USA
| | - William Tse
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY, 40202, USA
| | - Donghan Lee
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY, 40202, USA.
| | - T Michael Sabo
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY, 40202, USA.
| |
Collapse
|
2
|
Khan N, Shah PP, Ban D, Trigo-Mouriño P, Carneiro MG, DeLeeuw L, Dean WL, Trent JO, Beverly LJ, Konrad M, Lee D, Sabo TM. Solution structure and functional investigation of human guanylate kinase reveals allosteric networking and a crucial role for the enzyme in cancer. J Biol Chem 2019; 294:11920-11933. [PMID: 31201273 DOI: 10.1074/jbc.ra119.009251] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/12/2019] [Indexed: 01/13/2023] Open
Abstract
Human guanylate kinase (hGMPK) is the only known enzyme responsible for cellular GDP production, making it essential for cellular viability and proliferation. Moreover, hGMPK has been assigned a critical role in metabolic activation of antiviral and antineoplastic nucleoside-analog prodrugs. Given that hGMPK is indispensable for producing the nucleotide building blocks of DNA, RNA, and cGMP and that cancer cells possess elevated GTP levels, it is surprising that a detailed structural and functional characterization of hGMPK is lacking. Here, we present the first high-resolution structure of hGMPK in the apo form, determined with NMR spectroscopy. The structure revealed that hGMPK consists of three distinct regions designated as the LID, GMP-binding (GMP-BD), and CORE domains and is in an open configuration that is nucleotide binding-competent. We also demonstrate that nonsynonymous single-nucleotide variants (nsSNVs) of the hGMPK CORE domain distant from the nucleotide-binding site of this domain modulate enzymatic activity without significantly affecting hGMPK's structure. Finally, we show that knocking down the hGMPK gene in lung adenocarcinoma cell lines decreases cellular viability, proliferation, and clonogenic potential while not altering the proliferation of immortalized, noncancerous human peripheral airway cells. Taken together, our results provide an important step toward establishing hGMPK as a potential biomolecular target, from both an orthosteric (ligand-binding sites) and allosteric (location of CORE domain-located nsSNVs) standpoint.
Collapse
Affiliation(s)
- Nazimuddin Khan
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202
| | - Parag P Shah
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202
| | - David Ban
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202
| | - Pablo Trigo-Mouriño
- Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Marta G Carneiro
- Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Lynn DeLeeuw
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202
| | - William L Dean
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202
| | - John O Trent
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202
| | - Levi J Beverly
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202
| | - Manfred Konrad
- Enzyme Biochemistry Group, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Donghan Lee
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202
| | - T Michael Sabo
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky 40202
| |
Collapse
|
3
|
Crowley EL, Rafferty SP. Review of lactose-driven auto-induction expression of isotope-labelled proteins. Protein Expr Purif 2019; 157:70-85. [PMID: 30708035 DOI: 10.1016/j.pep.2019.01.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 01/18/2019] [Indexed: 02/06/2023]
Abstract
NMR is an important method in the structural and functional characterization of proteins, but such experiments typically require isotopic labelling because of the low natural abundance of the nuclei of interest. Isotope-labelled protein for NMR experiments is typically obtained from IPTG-inducible bacterial expression systems in a minimal media that contains labelled carbon or nitrogen sources. Optimization of expression conditions is crucial yet challenging; large amounts of labelled protein are desired, yet protein yields are lower in minimal media, while the labelled precursors are expensive. Faced with these challenges there is a growing body of literature that apply innovative methods of induction to optimize the yield of isotope-labelled protein. A promising technique is lactose-driven auto-induction as it mitigates user intervention and can lead to higher protein yields. This review assesses the current advances and limitations surrounding the ability of researchers to isotope label proteins using auto-induction, and it identifies key components for optimization.
Collapse
Affiliation(s)
- Erika L Crowley
- Environmental and Life Sciences Graduate Program, Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 0G2, Canada.
| | - Steven P Rafferty
- Department of Chemistry, Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 0G2, Canada.
| |
Collapse
|