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Medical Biochemistry Commons

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Pharmacy Faculty Articles and Research

2021

Small-conductance Ca2+-activated potassium channel

Articles 1 - 1 of 1

Full-Text Articles in Medical Biochemistry

Subtype-Selective Positive Modulation Of KCa 2 Channels Depends On The Ha/Hb Helices, Young-Woo Nam, Meng Cui, Naglaa Salem, Razan Orfali, Misa Nguyen, Grace Yang, Mohammad Asikur Rahman, Judy Lee, Miao Zhang Aug 2021

Subtype-Selective Positive Modulation Of KCa 2 Channels Depends On The Ha/Hb Helices, Young-Woo Nam, Meng Cui, Naglaa Salem, Razan Orfali, Misa Nguyen, Grace Yang, Mohammad Asikur Rahman, Judy Lee, Miao Zhang

Pharmacy Faculty Articles and Research

Background and Purpose

In the activated state of small-conductance Ca2+-activated potassium (KCa 2) channels, calmodulin interacts with the HA/HB helices and the S4-S5 linker. CyPPA potentiates KCa 2.2a and KCa 2.3 channel activity but not the KCa 2.1 and KCa 3.1 subtypes.

Experimental Approach

Site-directed mutagenesis, patch-clamp recordings and in silico modeling were utilized to explore the structural determinants for the subtype-selective modulation of KCa 2 channels by CyPPA.

Key Results

Mutating residues in the HA (V420) and HB (K467) helices of KCa 2.2a channels to their equivalent residues in KCa 3.1 channels diminished the potency of CyPPA. CyPPA elicited …