Imaging mobile zinc in biology

Tomat, Elisa; Lippard, Stephen J.

doi:10.1016/j.cbpa.2009.12.010

Cited by 202 publications

(117 citation statements)

References 55 publications

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“…With the growing recognition that labile Zn 2þ plays important roles in influencing signaling pathways and cellular functions, there has been extensive effort over the past few years to develop fluorescent sensors for monitoring Zn 2þ fluxes in cells (5,15,32,33). Previously we developed two zinc sensors that utilized a single zinc finger from Zif268 as the sensing module (ZifCY1…”

Section: Discussionmentioning

confidence: 99%

Measuring steady-state and dynamic endoplasmic reticulum and Golgi Zn ²⁺ with genetically encoded sensors

Qin

Dittmer

Park

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

279

350

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Zn 2+ plays essential roles in biology, and cells have adopted exquisite mechanisms for regulating steady-state Zn 2+ levels. Although much is known about total Zn 2+ in cells, very little is known about its subcellular distribution. Yet defining the location of Zn 2+ and how it changes with signaling events is essential for elucidating how cells regulate this essential ion. Here we create fluorescent sensors genetically targeted to the endoplasmic reticulum (ER) and Golgi to monitor steady-state Zn 2+ levels as well as flux of Zn 2+ into and out of these organelles. These studies reveal that ER and Golgi contain a concentration of free Zn 2+ that is 100 times lower than the cytosol. Both organelles take up Zn 2+ when cytosolic levels are elevated, suggesting that the ER and Golgi can sequester elevated cytosolic Zn 2+ and thus have the potential to play a role in influencing Zn 2+ toxicity. ER Zn 2+ homeostasis is perturbed by small molecule antagonists of Ca 2+ homeostasis and ER Zn 2+ is released upon elevation of cytosolic Ca 2+ pointing to potential exchange of these two ions across the ER. This study provides direct evidence that Ca 2+ signaling can influence Zn 2+ homeostasis and vice versa, that Zn 2+ dynamics may modulate Ca 2+ signaling.

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Section: Discussionmentioning

confidence: 99%

Measuring steady-state and dynamic endoplasmic reticulum and Golgi Zn ²⁺ with genetically encoded sensors

Qin

Dittmer

Park

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

279

350

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“…The development of innovative fluorescent imaging probes has revolutionized cell biology, allowing localization and dynamic monitoring of cellular metabolite and inorganic ion pools 15,16,[24][25][26][27][28][29] . A significant bottleneck in the emerging field of H 2 S/aqueous sulphide signalling is the absence of technology for effective in vivo detection and imaging, a problem that is exacerbated by the high intracellular thiol concentration.…”

Section: Discussionmentioning

confidence: 99%

Selective fluorescent probes for live-cell monitoring of sulphide

et al. 2011

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Aqueous sulphides, including hydrogen sulphide, have important roles in biological signalling and metabolic processes. Here we develop a selective sulphide-trapping strategy involving sulphide addition to an aldehyde; the resulting hemithioacetal undergoes a michael addition with an adjacent unsaturated acrylate ester to form a thioacetal at neutral pH in aqueous solution. Employing this new strategy, two sulphide-selective fluorescent probes, sFP-1 and sFP-2, were synthesized on the basis of two different fluorophore templates. These probes exhibit an excellent fluorescence increase and an emission maximum shift (sFP-1) in response to na 2 s and H 2 s in a high thiol background as found under physiological conditions. We show the utility of the probes for the selective detection of sulphides, and the capacity of our probes to monitor enzymatic H 2 s biogenesis and image free sulphide in living cells.

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“…On stimulation, these cells likewise corelease Zn 2+ , together with other secretory granules' contents, into the extracellular medium (32). These different biological systems may also represent fertile areas to apply ZIMIR or its homologs to study stimulus-secretion coupling and Zn 2+ homeostasis (33). Depending on the cell type and/or the biological preparation, local [Zn 2+ ] fluctuations near the cell surface likely vary over a wide range during secretion.…”

Section: Discussionmentioning

confidence: 99%

Imaging dynamic insulin release using a fluorescent zinc indicator for monitoring induced exocytotic release (ZIMIR)

Chen

Bellomo

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

146

176

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Current methods of monitoring insulin secretion lack the required spatial and temporal resolution to adequately map the dynamics of exocytosis of native insulin granules in intact cell populations in three dimensions. Exploiting the fact that insulin granules contain a high level of Zn 2+ , and that Zn 2+ is coreleased with insulin during secretion, we have developed a fluorescent, cell surface-targeted zinc indicator for monitoring induced exocytotic release (ZIMIR). ZIMIR displayed a robust fluorescence enhancement on Zn 2+ chelation and bound Zn 2+ with high selectivity against Ca 2+ and Mg 2+ . When added to cultured β cells or intact pancreatic islets at low micromolar concentrations, ZIMIR labeled cells rapidly, noninvasively, and stably, and it reliably reported changes in Zn 2+ concentration near the sites of granule fusion with high sensitivity that correlated well with membrane capacitance measurement. Fluorescence imaging of ZIMIR-labeled β cells followed the dynamics of exocytotic activity at subcellular resolution, even when using simple epifluorescence microscopy, and located the chief sites of insulin release to intercellular junctions. Moreover, ZIMIR imaging of intact rat islets revealed that Zn 2+ /insulin release occurred largely in small groups of adjacent β cells, with each forming a "secretory unit." Concurrent imaging of ZIMIR and Fura-2 showed that the amplitude of cytosolic Ca 2+ elevation did not necessarily correlate with insulin secretion activity, suggesting that events downstream of Ca 2+ signaling underlie the cell-cell heterogeneity in insulin release. In addition to studying stimulation-secretion coupling in cells with Zn 2+ -containing granules, ZIMIR may find applications in β-cell engineering and screening for molecules regulating insulin secretion on high-throughput platforms.probe development | zinc imaging | hormone secretion assay

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Imaging mobile zinc in biology

Cited by 202 publications

References 55 publications

Measuring steady-state and dynamic endoplasmic reticulum and Golgi Zn ²⁺ with genetically encoded sensors

Measuring steady-state and dynamic endoplasmic reticulum and Golgi Zn ²⁺ with genetically encoded sensors

Selective fluorescent probes for live-cell monitoring of sulphide

Imaging dynamic insulin release using a fluorescent zinc indicator for monitoring induced exocytotic release (ZIMIR)

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Imaging mobile zinc in biology

Cited by 202 publications

References 55 publications

Measuring steady-state and dynamic endoplasmic reticulum and Golgi Zn 2+ with genetically encoded sensors

Measuring steady-state and dynamic endoplasmic reticulum and Golgi Zn 2+ with genetically encoded sensors

Selective fluorescent probes for live-cell monitoring of sulphide

Imaging dynamic insulin release using a fluorescent zinc indicator for monitoring induced exocytotic release (ZIMIR)

Contact Info

Product

Resources

About

Measuring steady-state and dynamic endoplasmic reticulum and Golgi Zn ²⁺ with genetically encoded sensors

Measuring steady-state and dynamic endoplasmic reticulum and Golgi Zn ²⁺ with genetically encoded sensors