Characterization and mapping of the Rapsn gene encoding the 43-kDa acetylcholine receptor-associated protein.

We have cloned and characterized mouse genomic DNA containing the gene for the 43-kDa acetylcholine receptor-associated protein. The gene extends over 12 kb and consists of 8 exons. RNase protection and sequence analysis have been used to define the intron/exon boundaries including 174 and 214 bp of 5' and 3' untranslated sequence in exons 1 and 8, respectively.

Human potassium channel genes: Molecular cloning and functional expression.

Complementary DNAs representing three voltage-gated K(+) channels from humans (HuKI, HuKII, and HuKIV) were isolated, their nucleotide sequences determined, and their functional products examined electrophysiologically. The three human K(+) channels are closely related to the Shaker gene of Drosophila and possess several canonical structural features including multiple hydrophobic segments which are potentially membrane spanning, a positively charged S4 segment which may be the voltage sensor, and a leucine heptad repeat which may be involved in channel gating. Members of the human gene family have specific, highly conserved homologs in rodents, suggesting that the individual members arose prior to the mammalian radiation.

Alteration of potassium channel gating: molecular analysis of the Drosophila Sh5 mutation.

The Drosophila Shaker (Sh) gene encodes a family of voltage-gated K+ channels. Mutant alleles of Sh alter the currents expressed from these channels in a variety of ways. To identify the molecular basis of these alterations, Sh transcript sequences were amplified using the polymerase chain reaction after reverse transcription of mutant RNA.

Spectrophotometric determination of chromium(III) and rhodium(III) after extraction with oxine into molten naphthalene.

Conditions have been developed for the extraction of chromium(III) and rhodium(III) as their 8-hydroxyquinolinates into molten naphthalene. The naphthalene is allowed to solidify, separated by filtration, dried with filter paper and dissolved in chloroform. The solution is diluted to 10 ml and its absorbance measured at 410 nm for chromium and 425 nm for rhodium, against a reagent blank.