Kai Johnsson

Fast calcium-dependent fluorescent labeling for recording of neuronal activation

The paper introduces faster variants of the Caprola tool for calcium-dependent fluorescent labeling, enabling more sensitive and efficient recording of neuronal activity in zebrafish.

Collective cancer cell calcium activity drives brain metastasis

The paper shows brain metastases form gap-junction-coupled networks with coordinated calcium activity that drives proliferation and is inhibited by gap junction blockers.

Localizable fluorescent metal ion indicators with tunable colors

The paper introduces a modular strategy to create fluorescent metal ion indicators with tunable colors and subcellular localization, demonstrating their use in live-cell potassium sensing in rat hippocampal neurons.

A high-affinity split-HaloTag for live-cell protein labeling

This paper introduces a high-affinity split-HaloTag system for live-cell protein labeling, enabling efficient and versatile imaging with compatibility for advanced microscopy techniques.

Fast and Luminous: CLIP-tag2

The paper introduces CLIP-tag2, an engineered variant of the CLIP-tag protein that significantly improves labeling speed and efficiency for live-cell imaging.

SiR-XActin: A fluorescent probe for imaging actin dynamics in live cells

The paper introduces SiR-XActin, a far-red fluorescent probe for imaging actin dynamics in live cells with minimal cytotoxicity and without genetic modifications.

Molecular recording of cellular protein kinase activity with chemical labeling

The paper introduces molecular recorders to track kinase activity in cells and applies them to study PKA activity and neuromodulation.

Fast, Bright and Reversible Rhodamine Tags for Live-Cell Imaging

This paper introduces Rho-tag and SiR-tag, fast, reversible, and fluorogenic protein tags for live-cell imaging, compatible with super-resolution techniques and demonstrated in zebrafish larvae.

SNAP-tag2: faster and brighter protein labeling

This paper introduces SNAP-tag2, an improved version of SNAP-tag with faster labeling kinetics and higher fluorescence brightness for better live-cell imaging.

In vivo multiplex imaging of dynamic neurochemical networks with designed far-red dopamine sensors

The paper introduces a far-red dopamine sensor, HaloDA1.0, enabling multiplex imaging of neurochemical networks in vivo with high sensitivity and versatility.

Improving Split-HaloTag through Computational Protein Engineering

This paper improves split-HaloTag by engineering cpHalo{Delta} with computational methods to enhance thermostability and activity, reducing assay time and substrate requirements.

A silicon rhodamine-fused glibenclamide to label and detect malaria-infected red blood cells

This paper develops a fluorescent probe to detect malaria-infected red blood cells and demonstrates its use with a smartphone microscope for diagnostic applications.

Long-term single-molecule tracking in living cells using weak-affinity protein labeling

This paper introduces a labeling method for long-term single-molecule tracking in living cells and demonstrates its application to study EGFR dynamics.

Fluorescent and bioluminescent calcium indicators with tuneable colors and affinities

This paper introduces a family of tunable calcium indicators with fluorescence and bioluminescence readouts, applicable for live-cell imaging and high-throughput assays in rat neurons.

Chemogenetic control of nanobodies

This paper describes an engineered nanobody that modulates GFP binding with small molecules, enabling controlled study of GFP fusion proteins in biological processes.

A chemogenetic approach for optical monitoring of voltage in neurons

The paper introduces a chemogenetic tool for optical voltage monitoring in neurons using a fluorescent probe that detects both supra- and subthreshold activity.

Control of mechanical pain hypersensitivity through ligand-targeted photoablation of TrkB positive sensory neurons

This study identifies TrkB-expressing sensory neurons as key to mechanical allodynia and demonstrates their ablation as a treatment for neuropathic pain.