The fungal alkaloid Okaramine-B activates an L-glutamate-gated chloride channel from Ixodes scapularis, a tick vector of Lyme disease.

ABSTRACT: A novel L-glutamate-gated anion channel (IscaGluCl1) has been cloned from the black-legged tick, Ixodes scapularis, which transmits multiple pathogens including the agents of Lyme disease and human granulocytic anaplasmosis. When mRNA encoding IscaGluCl1 was expressed in Xenopus laevis oocytes, we detected robust 50-400 nA currents in response to 100 μM L-glutamate. Responses to L-glutamate were concentration-dependent (pEC₅₀ 3.64 ± 0.11). Ibotenate was a partial agonist on IscaGluCl1. We detected no response to 100 μM aspartate, quisqualate, kainate, AMPA or NMDA. Ivermectin at 1 μM activated IscaGluCl1, whereas picrotoxinin (pIC₅₀ 6.20 ± 0.04) and the phenylpyrazole fipronil (pIC₅₀ 6.90 ± 0.04) showed concentration-dependent block of the L-glutamate respo

SUBMITTER: Furutani S 

PROVIDER: S-EPMC6039357 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature