Slowpoke-like potassium channel 1 (SLO-1) (SLO-1)

Slowpoke-like potassium channel 1 (SLO-1) is a large-conductance, calcium-activated potassium (BK) channel primarily expressed in the neurons and muscles of nematodes (NIH, 2007). It serves as a critical regulator of cellular excitability, influencing essential behaviors such as locomotion, feeding (pharyngeal pumping), and egg-laying (NIH, 2011). The channel is the primary molecular target for the anthelmintic drug emodepside, a cyclooctadepsipeptide used to treat a variety of parasitic infections (PLOS, 2014). Emodepside acts as a potent activator of SLO-1, inducing a prolonged opening of the channel that leads to potassium efflux and membrane hyperpolarization (NIH, 2024). This physiological response results in flaccid paralysis and the eventual death of the parasite (PLOS, 2014). SLO-1 is highly conserved across nematode species, making it an effective target for broad-spectrum anthelmintic therapy (NIH, 2011). Although orthologs exist in mammals (e.g., KCNMA1), emodepside demonstrates a high degree of selectivity for the nematode version of the channel, which minimizes adverse effects on the host (PLOS, 2014). Resistance to emodepside has been linked to specific mutations in the slo-1 gene, highlighting its central role in the drug's efficacy (NIH, 2007). Understanding the structural and functional properties of SLO-1 continues to be a focus for developing new treatments against resistant helminth populations (NIH, 2024).

Other names

BK channelMaxi-K channelLarge conductance calcium-activated potassium channelslo-1

Emodepside acts as a SLO-1 agonist, increasing the open probability of the channel, which leads to potassium efflux, membrane hyperpolarization, and flaccid paralysis of the nematode (NIH, 2011; PLOS, 2014).