Protein KIBRA also known as kidney and brain expressed protein (KIBRA) or WW domain-containing protein 1 (WWC1) is a protein that in humans is encoded by the WWC1 gene.[5][6][7]
A single nucleotide polymorphism (rs17070145) [8] in the gene has been associated with human memory performance and cognitive ability in various studies since 2006. While no significant support for KIBRA's association with memory was found in a 2008 study with 584 subjects,[9] the original 2006 study was replicated in a smaller sample of an elderly population in 2008[10] Two subsequent studies in 2009 in indicated that KIBRA is specifically associated with forgetting of non-semantic material as well as cognitive flexibility among smokers and non-smokers.[11] KIBRA SNPs have been shown to increase hippocampal volume and affect spatial ability and scientific achievement.[12][13]
Studies have also begun to investigate the role of KIBRA in Alzheimer's disease.[14]
KIBRA has at least 10 interaction partners, including synaptopodin, PKCζ and Dendrin, most of which modify synaptic plasticity. For instance, Dendrin is a post-synaptic protein with expression regulated by sleep deprivation.[15] KIBRA has been shown to interact with Protein kinase Mζ.[16]