Abstract:
:Recent work has introduced a new fluorescent voltage sensor, ASAP1, which can monitor rapid trains of action potentials in cultured neurons. This indicator is based on the Gallus gallus voltage-sensitive phosphatase with the phosphatase domain removed and a circularly permuted GFP placed in the S3-S4 linker. However, many of the biophysical details of this indicator remain unknown. In this work, we study the biophysical properties of ASAP1. Using the cut-open voltage clamp technique, we have simultaneously recorded fluorescence signals and gating currents from Xenopus laevis oocytes expressing ASAP1. Gating charge movement and fluorescence kinetics track closely with each other, although ASAP1 gating currents are significantly faster than those of Ciona intestinalis voltage-sensitive phosphatase. Altering the residue before the first gating charge removes a split in the ASAP1 QV curve, but preserves the accelerated kinetics that allow for the faithful tracking of action potentials in neurons.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Lee EEL,Bezanilla Fdoi
10.1016/j.bpj.2017.10.018subject
Has Abstractpub_date
2017-11-21 00:00:00pages
2178-2181issue
10eissn
0006-3495issn
1542-0086pii
S0006-3495(17)31133-5journal_volume
113pub_type
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