1
|
Pimenta FM, Huh J, Guzman B, Amanah D, Marston DJ, Pinkin NK, Danuser G, Hahn KM. Rho MultiBinder, a fluorescent biosensor that reports the activity of multiple GTPases. Biophys J 2023; 122:3646-3655. [PMID: 37085995 PMCID: PMC10541480 DOI: 10.1016/j.bpj.2023.04.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Received: 08/24/2022] [Revised: 02/28/2023] [Accepted: 04/17/2023] [Indexed: 04/23/2023] Open
Abstract
Imaging two or more fluorescent biosensors in the same living cell can reveal the spatiotemporal coordination of protein activities. However, using multiple Förster resonance energy transfer (FRET) biosensors together is challenging due to toxicity and the need for orthogonal fluorophores. Here we generate a biosensor component that binds selectively to the activated conformation of three different proteins. This enabled multiplexed FRET with fewer fluorophores, and reduced toxicity. We generated this MultiBinder (MB) reagent for the GTPases RhoA, Rac1, and Cdc42 by combining portions of the downstream effector proteins Pak1 and Rhotekin. Using FRET between mCherry on the MB and YPet or mAmetrine on two target proteins, the activities of any pair of GTPases could be distinguished. The MB was used to image Rac1 and RhoA together with a third, dye-based biosensor for Cdc42. Quantifying effects of biosensor combinations on the frequency, duration, and velocity of cell protrusions and retractions demonstrated reduced toxicity. Multiplexed imaging revealed signaling hierarchies between the three proteins at the cell edge where they regulate motility.
Collapse
Affiliation(s)
- Frederico M Pimenta
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jaewon Huh
- Departments of Bioinformatics and Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Bryan Guzman
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Diepreye Amanah
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Daniel J Marston
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Nicholas K Pinkin
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Gaudenz Danuser
- Departments of Bioinformatics and Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Klaus M Hahn
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
| |
Collapse
|
2
|
Liu B, Pinkin NK, Pimenta FM, Hahn KM. A new biosensor design reveals conformational changes of single molecules in living cells. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.2612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
|
3
|
MacNevin CJ, Watanabe T, Weitzman M, Gulyani A, Fuehrer S, Pinkin NK, Tian X, Liu F, Jin J, Hahn KM. Membrane-Permeant, Environment-Sensitive Dyes Generate Biosensors within Living Cells. J Am Chem Soc 2019; 141:7275-7282. [PMID: 30994345 DOI: 10.1021/jacs.8b09841] [Citation(s) in RCA: 22] [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: 02/06/2023]
Abstract
Dyes with environment-sensitive fluorescence have proven useful to study the spatiotemporal dynamics of protein activity in living cells. When attached to proteins, their fluorescence can reflect protein conformational changes, post-translational modifications, or protein interactions. However, the utility of such dye-protein conjugates has been limited because it is difficult to load them into cells. They usually must be introduced using techniques that perturb cell physiology, limit throughput, or generate fluorescent vesicles (e.g., electroporation, microinjection, or membrane transduction peptides). Here we circumvent these problems by modifying a proven, environment-sensitive biosensor fluorophore so that it can pass through cell membranes without staining intracellular compartments and can be attached to proteins within living cells using unnatural amino acid (UAA) mutagenesis. Reactive groups were incorporated for attachment to UAAs or small molecules (mero166, azide; mero167, alkyne; mero76, carboxylic acid). These dyes are bright and fluoresce at long wavelengths (reaching ε = 100 000 M-1 cm-1, ϕ = 0.24, with excitation 565 nm and emission 594 nm). The utility of mero166 was demonstrated by in-cell labeling of a UAA to generate a biosensor for the small GTPase Cdc42. In addition, conjugation of mero166 to a small molecule produced a membrane-permeable probe that reported the localization of the DNA methyltransferase G9a in cells. This approach provides a strategy to access biosensors for many targets and to more practically harness the varied environmental sensitivities of synthetic dyes.
Collapse
Affiliation(s)
- Christopher J MacNevin
- Department of Pharmacology, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Takashi Watanabe
- Department of Pharmacology, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Matthew Weitzman
- Department of Pharmacology, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Akash Gulyani
- Department of Pharmacology, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Sheryl Fuehrer
- Department of Pharmacology, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Nicholas K Pinkin
- Department of Pharmacology, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Xu Tian
- Department of Pharmacology, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Feng Liu
- Center for Integrative Chemical Biology and Drug Discovery, School of Pharmacy , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Jian Jin
- Center for Integrative Chemical Biology and Drug Discovery, School of Pharmacy , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Klaus M Hahn
- Department of Pharmacology, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| |
Collapse
|
4
|
Mullins AG, Pinkin NK, Hardin JA, Waters ML. Achieving High Affinity and Selectivity for Asymmetric Dimethylarginine by Putting a Lid on a Box. Angew Chem Int Ed Engl 2019; 58:5282-5285. [DOI: 10.1002/anie.201814645] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/30/2019] [Indexed: 01/01/2023]
Affiliation(s)
- Alexandria G. Mullins
- Department of Chemistry, CB 3290University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599 USA
| | - Nicholas K. Pinkin
- Department of Chemistry, CB 3290University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599 USA
| | - Joshua A. Hardin
- Department of Chemistry, CB 3290University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599 USA
| | - Marcey L. Waters
- Department of Chemistry, CB 3290University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599 USA
| |
Collapse
|
5
|
Mullins AG, Pinkin NK, Hardin JA, Waters ML. Achieving High Affinity and Selectivity for Asymmetric Dimethylarginine by Putting a Lid on a Box. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201814645] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Alexandria G. Mullins
- Department of Chemistry, CB 3290University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599 USA
| | - Nicholas K. Pinkin
- Department of Chemistry, CB 3290University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599 USA
| | - Joshua A. Hardin
- Department of Chemistry, CB 3290University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599 USA
| | - Marcey L. Waters
- Department of Chemistry, CB 3290University of North Carolina at Chapel Hill Chapel Hill North Carolina 27599 USA
| |
Collapse
|
6
|
Abstract
Small molecule receptors are attractive potential sensors of post-translational modifications, including methylated lysine and methylated arginine. Using dynamic combinatorial chemistry (DCC), our lab previously identified a suite of receptors that bind to Kme3 with a range of affinities ranging from low micromolar to high nanomolar, each with a unique selectivity for Kme3 over the lower methylation states. To enable these receptors to have broad application as Kme3 sensors, we have developed a method for their late-stage modification, which we used to synthesize biotinylated derivatives of A2B, A2D, and A2G in a single step. For our most attractive receptor for applications, A2N, we needed to develop an alternative method for its selective functionalization, which we achieved by "activating" the carboxylic acids on the constituent monomer A or N by pre-functionalizing them with glycine (Gly). Using the resulting Gly-A and Gly-N monomers, we synthesized the novel A2N variants A2Gly-N, Gly-A2N, and Gly-A2Gly-N, which enabled the late stage biotinylation of A2N wherever Gly was incorporated. Finally, we performed ITC and NMR binding experiments to study the effect that carboxylate spacing has on the affinity and selectivity of A2Gly-N and Gly-A2N for KmeX guests compared to A2N. These studies revealed the proximity of the carboxylates to play a complex role in the molecular recognition event, despite their positioning on the outside of the receptor.
Collapse
Affiliation(s)
- Nicholas K Pinkin
- Department of Chemistry, CB 3290, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | | | | |
Collapse
|
8
|
Pinkin NK, Waters ML. Development and mechanistic studies of an optimized receptor for trimethyllysine using iterative redesign by dynamic combinatorial chemistry. Org Biomol Chem 2014; 12:7059-67. [DOI: 10.1039/c4ob01249f] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Iterative monomer redesign leads to a Kme3-peptide receptor with 10-fold tighter affinity and 5-fold improved selectivity over Kme2 than the original receptor. Thermodynamic analysis provides insight into this improvement.
Collapse
|