TY - JOUR
T1 - An episodic ataxia type-1 mutation in the S1 segment sensitises the hKv1.1 potassium channel to extracellular Zn2+
AU - Cusimano, Antonella
AU - Cristina D'Adamo, Maria
AU - Pessia, Mauro
N1 - Funding Information:
We thank Stephen Tucker and Paola Imbrici for critically reading the manuscript. The financial support of Telethon-Italy (Grant no. GGP030159), of MIUR-COFIN 2003 and of COMPAGNIA di San Paolo (Turin) is gratefully acknowledged. We thank Domenico Bambagioni and Ezio Mezzasoma for invaluable technical assistance. Antonella Cusimano is the recipient of a fellowship from COMPAGNIA di San Paolo (Turin).
PY - 2004/10/8
Y1 - 2004/10/8
N2 - Episodic ataxia type-1 (EA1) is a human neurological syndrome characterized by attacks of generalized ataxia and by continuous myokymia that has been associated with point mutations in the voltage-gated potassium channel gene KCNA1. Although important advancement has been made in understanding the molecular pathophysiology of EA1, several disease-causing mechanisms remain poorly understood. F184C is an EA1 mutation that is located within the S1 segment of the human Kv1.1 subunit. Here, we show that the F184C mutation increases ∼4.5-fold the sensitivity of the channel to extracellular Zn 2+. Both Zn2+ and Cd2+ markedly alter the activation kinetics of F184C channel. In addition, the mutated channel reacts with several methane thiosulfonate reagents which specifically affected channel function. The results provide structural implications and indicate that sensitisation of hKv1.1 to Zn2+ is likely to contribute to the EA1 symptoms in patients harboring the F184C mutation.
AB - Episodic ataxia type-1 (EA1) is a human neurological syndrome characterized by attacks of generalized ataxia and by continuous myokymia that has been associated with point mutations in the voltage-gated potassium channel gene KCNA1. Although important advancement has been made in understanding the molecular pathophysiology of EA1, several disease-causing mechanisms remain poorly understood. F184C is an EA1 mutation that is located within the S1 segment of the human Kv1.1 subunit. Here, we show that the F184C mutation increases ∼4.5-fold the sensitivity of the channel to extracellular Zn 2+. Both Zn2+ and Cd2+ markedly alter the activation kinetics of F184C channel. In addition, the mutated channel reacts with several methane thiosulfonate reagents which specifically affected channel function. The results provide structural implications and indicate that sensitisation of hKv1.1 to Zn2+ is likely to contribute to the EA1 symptoms in patients harboring the F184C mutation.
KW - Cadmium
KW - Episodic ataxia type-1
KW - KCNA1
KW - MTSEA, (2-aminoethyl) methane thiosulfonate
KW - MTSES, (2-sulfonatoethyl) methane thiosulfonate
KW - MTSET, (2-trimethylammoniumethyl) methane thiosulfonate
KW - Voltage-gated potassium channel
KW - Zinc
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U2 - 10.1016/j.febslet.2004.09.018
DO - 10.1016/j.febslet.2004.09.018
M3 - Article
C2 - 15474044
AN - SCOPUS:4944228311
SN - 0014-5793
VL - 576
SP - 237
EP - 244
JO - FEBS Letters
JF - FEBS Letters
IS - 1-2
ER -