ChEST reveals this is a target of Mef2.

The flight defect of slo null mutants arises from a lack of slo expression in muscle, whereas the "sticky-feet" phenotype arises from a lack of slo expression in nervous tissue.

14-3-3ζ can interact with and modulate slo via Slob.

Slob is identified as a protein that binds to the carboxy-terminal domain of slo in a yeast two-hybrid screen. Slob and slo co-immunoprecipitate from heads and heterologous host cells, suggesting they interact in vivo.

The region downstream of promoter C2 (exon C2 and exon C3) contains elements required for CNS expression, modulates expression in a developmental stage-specific manner and directs expression to the eye.

slo promoters are physically mapped and sequences responsible for the expression in the CNS, muscles and tracheal and midgut cells are functionally mapped.

Cloned slo channels in excised patches from Xenopus oocytes can exhibit large variability in gating properties, both within a single channel and among channels.

Mutation of slo causes a reduction of transmitter release at the neuromuscular junction. The slo mutation partially suppresses the increase in transmitter release caused by Sh mutants. The mutations confers suppression by reducing calcium influx into the nerve terminal.

Developmental and tissue-specific expression of slo.

Protein phosphorylation modulates the activity of slo channels expressed in Xenopus oocytes. Mutant channel protein can block the modulation by ATP-γS demonstrating that phosphorylation of the slo channel protein itself modulates channel activity.

Alternate splicing of a common slo RNA precursor contributes to the functional diversity of the encoded large conductance calcium-activated potassium channel. The variable region of the slo channel subunit comprises modular, yet interactive functional domains which influence the essential features of unit conductance, calcium sensitivity and gating of the channel.

Using PCR with nested primers and cloning from cDNA libraries, alternatively spliced versions predicting up to 144 different coding combinations were found. The existence of 31 of these was directly demonstrated. Excised inside out patch recordings show opening of the channel only when the Ca²⁺ is on the cytoplasmic side: opening increases both with depolarization and with increasing Ca²⁺ concentration. Single channel conductance is 126pS. Mean open times are different for different splice variants, proving that slo encodes a large family of functionally diverse Ca²⁺-activated K⁺ channels.

Effects of potassium channel blocking drugs on the presynaptic action potential repolarization after electrotonic stimulation was studied. At least four K⁺ currents contribute to repolarization of the nerve terminal.

Mutation analysis reveals that the slo polypeptide is essential for the expression or function of the channel mediating the fast Ca²⁺ activated K⁺ current.

Isolated in screen for third chromosomal temperature-sensitive paralytic mutants (Elkins, Ganetzky and Wu, 1986); this one is uncoordinated and unable to climb when exposed to 38^oC but not completely paralyzed; four-minute exposure to that high temperature causes several minutes of motionlessness on return to 22^oC. Legs shake when under ether anesthesia, as in Shaker mutants but less extreme. Unconditionally defective in behavior (e.g., diminished flight ability; tends to walk or fly in anomalous short hops when in large open container). Physiologically, the mutation abolishes Ca²⁺-dependent potassium current (I_C), as shown, and analyzed further, in a variety of experiments involving recordings from dorsal longitudinal flight muscles (DLMs) of adults (Elkins, Ganetzky and Wu, 1986; Elkins and Ganetzky, 1988): DLM spikes abnormally broadened after stimulation of giant fiber nerve pathway (one of whose endpoints is DLMs) or of motor neurons synapsing on these muscles. From voltage clamp analyses, a peak of early outward current following a step pulse from -80 to -40 mV, as revealed by a Sh mutation, is absent in slo, though inward Ca²⁺ currents in same traces are normal; no early outward current seen when slo is treated with 4-aminopyridine (which phenocopies Sh) or combined with Sh¹⁴. (This double mutant has very low viability and severe impairment in locomotor activity); charybdotoxin, which blocks I_C channels in wild-type DLMs, had no effect on outward currents in slo; delayed excitation of DLMs, observed in response to depolarizing currents delivered to wild-type (or Sh), absent in slo and spike amplitudes increased; these abnormalities phenocopied by reducing I_C in normal muscle by injecting EGTA into such cells or using low-Ca²⁺ saline; the lengthened muscle action potentials in slo indicate importance of I_C in effecting repolarization of such potentials.