High impact information on Kcnd1

• mShal, a subfamily of A-type K+ channel cloned from mammalian brain [1].
• Marked similarity was observed between mShal and its Drosophila homolog, fShal, with regard to voltage sensitivity of activation, macroscopic inactivation, steady-state inactivation, and 4-aminopyridine sensitivity [1].
• Mutant Analysis of the Shal (Kv4) Voltage-gated Fast Transient K+ Channel in Caenorhabditis elegans [2].
• Mutation of a Kv4-specific residue in the S4-S5 loop (C322S) of Kv4.1 also altered gating and 4-AP sensitivity in a manner that closely resembles the effects of V[404, 406]I [3].
• A previous study suggested that the cytoplasmic NH2- and COOH-terminal domains of Kv4.1 channels act in concert to determine the fast phase of the complex time course of macroscopic inactivation (Jerng, H.H., and M. Covarrubias. 1997. Biophys. J. 72:163-174) [3].

Biological context of Kcnd1

• Coexpression also modified the gating kinetics of mShal1 current in several respects [4].

Anatomical context of Kcnd1

• Expression of Shal potassium channel subunits in the adult and developing cochlear nucleus of the mouse [5].
• Coinjected oocytes exhibited a significant (fourfold) increase in the surface expression of mShal1 K+ channels with no change in the open-channel conductance [4].

Regulatory relationships of Kcnd1

• Although the techniques employed in this study detect mRNA and not protein, it can be inferred from the differential distribution of Kv4 transcripts that CN neurons selectively regulate the expression of Shal K(+) channels among individual neurons throughout development [5].
• The mechanisms of inactivation gating of the neuronal somatodendritic A-type K(+) current and the cardiac I(to) were investigated in Xenopus oocyte macropatches expressing Kv4.1 and Kv4.3 channels [6].

Other interactions of Kcnd1

• We also found that PACAP predominately uses a PLC-calcium pathway to modulate Kv4.1 and Kv4.2 expression [7].
• This study describes the developmental distribution of mRNA for the three Shal channel subunits Kv4.1, Kv4.2 and Kv4.3 within the mouse CN, as assessed with in situ hybridization and RT-PCR techniques [5].
• Quantitative PCR indicated that in colonic and jejunal tissue, Kv4.3 transcripts demonstrate greater relative abundance than transcripts encoding Kv4.1 or Kv4 [8].
• We report here the initial characterization of 18 mutations in the S3-S4 linker of the Shaker channel, including deletions, insertions, charge change, substitution of prolines, and chimeras replacing the 25-residue Shaker linker with 7- or 9-residue sequences from Shab, Shaw, or Shal [9].
• To investigate their mechanism of action, Kv4.1 or Kv4.3 were expressed in Xenopus laevis oocytes, either alone or together with KChIP1, and the K+ currents were recorded using the whole-oocyte voltage-clamp and patch-clamp methods [10].

References