The protein encoded by the KCNAB1 gene is a cytoplasmic potassium channel subunit that belongs to the shaker potassium channel beta subunit family.  The protein is a homotetramer and forms a heterooctamer by interacting with potassium channel alpha subunits.  It plays an important role in accelerating channel closure and modulating action potentials.  The closure of delayed rectifier potassium channels is mediated by the N-terminal domain of the protein through physical obstruction of the pore.

Due to its function, the KCNAB1 protein is involved in several regulatory processes such as the release of neurotransmitters, secretion of insulin, contraction of smooth muscles, regulation of heart beats and neuronal excitability making it an ideal candidate gene for neurological and cardiovascular studies. 

The KCNAB1 gene is located on the long arm of chromosome 3 and spans approximately 500 kb of genomic DNA with a coding sequence consisting of 22 exons.  As a consequence of alternative splicing, the gene encodes three isoforms of the KCNAB1 protein that differ in their N termini, namely: KvB1.1, KvB1.2 and KvB1.3.  The isoform KvB1.3 is made up of 419 amino acids and is about 46 kDA in size.  Isoforms 1 and 2 are made up of 401 and 408 amino acids, respectively.  Expression of the KCNAB1 gene has been found predominantly in the brain and heart.