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The voltage‐gated Ca 2+ release channel in the vacuolar membrane of sugar beet resides in two activity states
Author(s) -
Johannes Eva,
Sanders Dale
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)00424-8
Subject(s) - sugar beet , chemistry , membrane , sugar , channel (broadcasting) , membrane potential , biophysics , horticulture , food science , biochemistry , biology , telecommunications , computer science
The voltage‐gated Ca 2+ release channel in the vacuolar membrane of sugar beet tap roots resides in two states which show similar reversal potentials in biionic conditions but differ dramatically in their single channel current and open frequency. State I has a unitary Ca 2+ conductance of 3.9 ± 0.5 pS and channel openings are rare at vacuolar resting potentials. After spontaneous and reversible transition into State II the unitary Ca 2+ conductance increases three‐fold, accompanied by a concomitant rise in channel activity over the physiological voltage range. The 15‐ to 19‐fold increase in total Ca 2+ current after the State I to State II transition could play an essential role in channel activation during signal transduction.