High impact information on KCNAB1

• We report here the cloning of a voltage-gated K+ channel beta subunit, hKv beta 3, from adult human left ventricle that shows 84% and 74% amino acid sequence identity with the previously cloned rat Kv beta 1 and Kv beta 2 subunits, respectively [1].
• Coinjection of hKv beta 3 with a human cardiac delayed rectifier, hKv1.5, in Xenopus oocytes increased inactivation, induced an 18-mV hyperpolarizing shift in the activation curve, and slowed deactivation (tau = 8.0 msec vs. 35.4 msec at -50 mV). hKv beta 3 was localized to human chromosome 3 by using a human/rodent cell hybrid mapping panel [1].
• We found that all Kv beta subunits promote cell surface expression of coexpressed Kv1.2 alpha subunits in transfected COS-1 cells [2].
• Together, these data suggest that NADP(+) binding and/or the integrity of the binding pocket structure, but not catalytic activity, of Kv beta subunits is required for intracellular trafficking of Kv1 channel complexes in mammalian cells and for axonal targeting in neurons [2].
• This phenotype can be transferred to co-assembled Kv1 alpha- and Kv beta-subunits associated with Kv1.1 in neurons [3].

Biological context of KCNAB1

• Thus, the previously observed failure of N-terminal mutants of Kv beta1 to modulate inactivation kinetics of Kv1 family members is not simply due to a lack of subunit interaction [4].
• The human Kv beta 1.1 gene (KCNA1B) resides on chromosome 3, as indicated by somatic cell hybrid mapping [5].
• The Kv beta 1 open reading frame is divided into 14 exons [6].

Anatomical context of KCNAB1

• Our results indicate that the hKv1.3 lymphocyte channel retains its electrophysiological characteristics when transfected in the Kv beta-negative HEK 293 cell line but its sensitivity to modulation by PKA and PKC is significantly reduced [7].

Associations of KCNAB1 with chemical compounds

• The beta subunit, Kv beta 1.2, acts as a rapid open channel blocker of NH2-terminal deleted Kv1.4 alpha-subunits [8].

Other interactions of KCNAB1

• Mammalian voltage-activated Shaker K+ channels associate with at least three cytoplasmic proteins: Kv beta 1, Kv beta 2 and Kv beta 3 [9].

Analytical, diagnostic and therapeutic context of KCNAB1

• Herein, the subunits comprising a number of neuronal K+ channels from bovine brain cortex were deduced by immunoprecipitation and Western blotting, using antibodies specific for Kv1.X and Kv beta subtypes [10].
• The expression of Kv 1 alpha and Kv beta mRNA was compared in Northern blots of poly(A+) RNA isolated from various human brain tissues [6].
• More precise localization of KCNA1B to 3q26.1 was obtained with fluorescence in situ hybridization (FISH) and was corroborated by PCR screening of the CEPH YAC library [5].
• Molecular cloning, immunopurification, and Western blot analysis demonstrated that an endogenous L-cell Kv beta 2.1 subunit assembled with transfected hKv 1.5 protein [11].

References