Filter
Associated Lab
- Ahrens Lab (2) Apply Ahrens Lab filter
- Aso Lab (1) Apply Aso Lab filter
- Betzig Lab (2) Apply Betzig Lab filter
- Beyene Lab (1) Apply Beyene Lab filter
- Branson Lab (2) Apply Branson Lab filter
- Card Lab (1) Apply Card Lab filter
- Cardona Lab (5) Apply Cardona Lab filter
- Clapham Lab (1) Apply Clapham Lab filter
- Dickson Lab (2) Apply Dickson Lab filter
- Dudman Lab (2) Apply Dudman Lab filter
- Espinosa Medina Lab (2) Apply Espinosa Medina Lab filter
- Feliciano Lab (1) Apply Feliciano Lab filter
- Funke Lab (3) Apply Funke Lab filter
- Harris Lab (2) Apply Harris Lab filter
- Heberlein Lab (1) Apply Heberlein Lab filter
- Hermundstad Lab (3) Apply Hermundstad Lab filter
- Hess Lab (5) Apply Hess Lab filter
- Jayaraman Lab (1) Apply Jayaraman Lab filter
- Karpova Lab (1) Apply Karpova Lab filter
- Keller Lab (2) Apply Keller Lab filter
- Lavis Lab (10) Apply Lavis Lab filter
- Lee (Albert) Lab (1) Apply Lee (Albert) Lab filter
- Lippincott-Schwartz Lab (14) Apply Lippincott-Schwartz Lab filter
- Liu (Zhe) Lab (6) Apply Liu (Zhe) Lab filter
- Looger Lab (11) Apply Looger Lab filter
- O'Shea Lab (1) Apply O'Shea Lab filter
- Pachitariu Lab (6) Apply Pachitariu Lab filter
- Podgorski Lab (1) Apply Podgorski Lab filter
- Reiser Lab (3) Apply Reiser Lab filter
- Romani Lab (4) Apply Romani Lab filter
- Rubin Lab (4) Apply Rubin Lab filter
- Saalfeld Lab (4) Apply Saalfeld Lab filter
- Scheffer Lab (2) Apply Scheffer Lab filter
- Schreiter Lab (1) Apply Schreiter Lab filter
- Spruston Lab (3) Apply Spruston Lab filter
- Stern Lab (5) Apply Stern Lab filter
- Sternson Lab (3) Apply Sternson Lab filter
- Stringer Lab (2) Apply Stringer Lab filter
- Svoboda Lab (7) Apply Svoboda Lab filter
- Tebo Lab (1) Apply Tebo Lab filter
- Tervo Lab (1) Apply Tervo Lab filter
- Tillberg Lab (3) Apply Tillberg Lab filter
- Truman Lab (3) Apply Truman Lab filter
- Turaga Lab (12) Apply Turaga Lab filter
- Turner Lab (1) Apply Turner Lab filter
- Zlatic Lab (1) Apply Zlatic Lab filter
Associated Project Team
Associated Support Team
- Cryo-Electron Microscopy (3) Apply Cryo-Electron Microscopy filter
- Electron Microscopy (1) Apply Electron Microscopy filter
- Fly Facility (3) Apply Fly Facility filter
- Integrative Imaging (2) Apply Integrative Imaging filter
- Janelia Experimental Technology (2) Apply Janelia Experimental Technology filter
- Molecular Genomics (2) Apply Molecular Genomics filter
- Primary & iPS Cell Culture (1) Apply Primary & iPS Cell Culture filter
- Project Technical Resources (3) Apply Project Technical Resources filter
- Quantitative Genomics (1) Apply Quantitative Genomics filter
- Scientific Computing Software (1) Apply Scientific Computing Software filter
- Viral Tools (2) Apply Viral Tools filter
Publication Date
- December 2021 (19) Apply December 2021 filter
- November 2021 (15) Apply November 2021 filter
- October 2021 (12) Apply October 2021 filter
- September 2021 (14) Apply September 2021 filter
- August 2021 (15) Apply August 2021 filter
- July 2021 (17) Apply July 2021 filter
- June 2021 (10) Apply June 2021 filter
- May 2021 (20) Apply May 2021 filter
- April 2021 (20) Apply April 2021 filter
- March 2021 (7) Apply March 2021 filter
- February 2021 (12) Apply February 2021 filter
- January 2021 (13) Apply January 2021 filter
- Remove 2021 filter 2021
174 Janelia Publications
Showing 161-170 of 174 resultsFunctional imaging using fluorescent indicators has revolutionized biology, but additional sensor scaffolds are needed to access properties such as bright, far-red emission. Here, we introduce a new platform for 'chemigenetic' fluorescent indicators, utilizing the self-labeling HaloTag protein conjugated to environmentally sensitive synthetic fluorophores. We solve a crystal structure of HaloTag bound to a rhodamine dye ligand to guide engineering efforts to modulate the dye environment. We show that fusion of HaloTag with protein sensor domains that undergo conformational changes near the bound dye results in large and rapid changes in fluorescence output. This generalizable approach affords bright, far-red calcium and voltage sensors with highly tunable photophysical and chemical properties, which can reliably detect single action potentials in cultured neurons.
The genetic and metabolic heterogeneity of RAS-driven cancers has confounded therapeutic strategies in the clinic. To address this, rapid and genetically tractable animal models are needed that recapitulate the heterogeneity of RAS-driven cancers in vivo. Here, we generate a Drosophila melanogaster model of Ras/Lkb1 mutant carcinoma. We show that low-level expression of oncogenic Ras (Ras) promotes the survival of Lkb1 mutant tissue, but results in autonomous cell cycle arrest and non-autonomous overgrowth of wild-type tissue. In contrast, high-level expression of oncogenic Ras (Ras) transforms Lkb1 mutant tissue resulting in lethal malignant tumors. Using simultaneous multiview light-sheet microcopy, we have characterized invasion phenotypes of Ras/Lkb1 tumors in living larvae. Our molecular analysis reveals sustained activation of the AMPK pathway in malignant Ras/Lkb1 tumors, and demonstrate the genetic and pharmacologic dependence of these tumors on CaMK-activated Ampk. We further show that LKB1 mutant human lung adenocarcinoma patients with high levels of oncogenic KRAS exhibit worse overall survival and increased AMPK activation. Our results suggest that high levels of oncogenic KRAS is a driving event in the malignant transformation of LKB1 mutant tissue, and uncovers a vulnerability that may be used to target this aggressive genetic subset of RAS-driven tumors.
Astrocytes are essential cells of the central nervous system, characterized by dynamic relationships with neurons that range from functional metabolic interactions and regulation of neuronal firing activities, to the release of neurotrophic and neuroprotective factors. In Parkinson’s disease (PD), dopaminergic neurons are progressively lost during the course of the disease, but the effects of PD on astrocytes and astrocyte-to-neuron communication remains largely unknown. This study focuses on the effects of the PD-related mutation LRRK2 G2019S in astrocytes generated from patient-derived induced pluripotent stem cells. We report the alteration of extracellular vesicle (EV) biogenesis in astrocytes, and we identify the abnormal accumulation of key PD-related proteins within multi vesicular bodies (MVBs). We found that dopaminergic neurons internalize astrocyte-secreted EVs and that LRRK2 G2019S EVs are abnormally enriched in neurites and fail to provide full neurotrophic support to dopaminergic neurons. Thus, dysfunctional astrocyte-to-neuron communication via altered EV biological properties may participate in the progression of PD.
Parvalbumin and somatostatin inhibitory interneurons gate information flow in discrete cortical areas that compute sensory and cognitive functions. Despite the considerable differences between areas, individual interneuron subtypes are genetically invariant and are thought to form canonical circuits regardless of which area they are embedded in. Here, we investigate whether this is achieved through selective and systematic variations in their afferent connectivity during development. To this end, we examined the development of their inputs within distinct cortical areas. We find that interneuron afferents show little evidence of being globally stereotyped. Rather, each subtype displays characteristic regional connectivity and distinct developmental dynamics by which this connectivity is achieved. Moreover, afferents dynamically regulated during development are disrupted by early sensory deprivation and in a model of fragile X syndrome. These data provide a comprehensive map of interneuron afferents across cortical areas and reveal the logic by which these circuits are established during development.
Approximately one-third of global CO fixation occurs in a phase-separated algal organelle called the pyrenoid. The existing data suggest that the pyrenoid forms by the phase separation of the CO-fixing enzyme Rubisco with a linker protein; however, the molecular interactions underlying this phase separation remain unknown. Here we present the structural basis of the interactions between Rubisco and its intrinsically disordered linker protein Essential Pyrenoid Component 1 (EPYC1) in the model alga Chlamydomonas reinhardtii. We find that EPYC1 consists of five evenly spaced Rubisco-binding regions that share sequence similarity. Single-particle cryo-electron microscopy of these regions in complex with Rubisco indicates that each Rubisco holoenzyme has eight binding sites for EPYC1, one on each Rubisco small subunit. Interface mutations disrupt binding, phase separation and pyrenoid formation. Cryo-electron tomography supports a model in which EPYC1 and Rubisco form a codependent multivalent network of specific low-affinity bonds, giving the matrix liquid-like properties. Our results advance the structural and functional understanding of the phase separation underlying the pyrenoid, an organelle that plays a fundamental role in the global carbon cycle.
Digital light microscopy provides powerful tools for quantitatively probing the real-time dynamics of subcellular structures. While the power of modern microscopy techniques is undeniable, rigorous record-keeping and quality control are required to ensure that imaging data may be properly interpreted (quality), reproduced (reproducibility), and used to extract reliable information and scientific knowledge which can be shared for further analysis (value). Keeping notes on microscopy experiments and quality control procedures ought to be straightforward, as the microscope is a machine whose components are defined and the performance measurable. Nevertheless, to this date, no universally adopted community-driven specifications exist that delineate the required information about the microscope hardware and acquisition settings (i.e., microscopy “data provenance” metadata) and the minimally accepted calibration metrics (i.e., microscopy quality control metadata) that should be automatically recorded by both commercial microscope manufacturers and customized microscope developers. In the absence of agreed guidelines, it is inherently difficult for scientists to create comprehensive records of imaging experiments and ensure the quality of resulting image data or for manufacturers to incorporate standardized reporting and performance metrics. To add to the confusion, microscopy experiments vary greatly in aim and complexity, ranging from purely descriptive work to complex, quantitative and even sub-resolution studies that require more detailed reporting and quality control measures.
The analysis of single particle trajectories plays an important role in elucidating dynamics within complex environments such as those found in living cells. However, the characterization of intracellular particle motion is often confounded by confinement of the particles within non-trivial subcellular geometries. Here, we focus specifically on the case of particles undergoing Brownian motion within a tubular network, as found in some cellular organelles. An unraveling algorithm is developed to uncouple particle motion from the confining network structure, allowing for an accurate extraction of the diffusion coefficient, as well as differentiating between Brownian and fractional Brownian dynamics. We validate the algorithm with simulated trajectories and then highlight its application to an example system: analyzing the motion of membrane proteins confined in the tubules of the peripheral endoplasmic reticulum in mammalian cells. We show that these proteins undergo diffusive motion with a well-characterized diffusivity. Our algorithm provides a generally applicable approach for disentangling geometric morphology and particle dynamics in networked architectures.
Neuroendocrine systems in animals maintain organismal homeostasis and regulate stress response. Although a great deal of work has been done on the neuropeptides and hormones that are released and act on target organs in the periphery, the synaptic inputs onto these neuroendocrine outputs in the brain are less well understood. Here, we use the transmission electron microscopy reconstruction of a whole central nervous system in the larva to elucidate the sensory pathways and the interneurons that provide synaptic input to the neurosecretory cells projecting to the endocrine organs. Predicted by network modeling, we also identify a new carbon dioxide-responsive network that acts on a specific set of neurosecretory cells and that includes those expressing corazonin (Crz) and diuretic hormone 44 (Dh44) neuropeptides. Our analysis reveals a neuronal network architecture for combinatorial action based on sensory and interneuronal pathways that converge onto distinct combinations of neuroendocrine outputs.
The importance of mechanical force in biology is evident across diverse length scales, ranging from tissue morphogenesis during embryo development to mechanotransduction across single adhesion proteins at the cell surface. Consequently, many force measurement techniques rely on optical microscopy to measure forces being applied by cells on their environment, to visualize specimen deformations due to external forces, or even to directly apply a physical perturbation to the sample via photoablation or optogenetic tools. Recent developments in advanced microscopy offer improved approaches to enhance spatiotemporal resolution, imaging depth, and sample viability. These advances can be coupled with already existing force measurement methods to improve sensitivity, duration and speed, amongst other parameters. However, gaining access to advanced microscopy instrumentation and the expertise necessary to extract meaningful insights from these techniques is an unavoidable hurdle. In this Live Cell Imaging special issue Review, we survey common microscopy-based force measurement techniques and examine how they can be bolstered by emerging microscopy methods. We further explore challenges related to the accompanying data analysis in biomechanical studies and discuss the various resources available to tackle the global issue of technology dissemination, an important avenue for biologists to gain access to pre-commercial instruments that can be leveraged for biomechanical studies.