In the middle of cortexin protein there is a single membrane-spanning domain which indicates that this protein may be a membrane protein involved in intracellular or extracellular signalling of the kidney or brain, since it is expressed specifically in the kidneys and brain only. The protein is highly conserved among species [1]. Cortexin is also thought to be important to neurons of both the developing and adult cerebral cortex [2].

1: In silico-initiated cloning and molecular characterization of cortexin 3, a novel human gene specifically expressed in the kidney and brain, and well conserved in vertebrates. Wang HT, Chang JW, Guo Z, Li BG; Int J Mol Med. 2007;20:501-510. PMID:17786280

2: Identification of cortexin: a novel, neuron-specific, 82-residue membrane protein enriched in rodent cerebral cortex. Coulter PM 2nd, Bautista EA, Margulies JE, Watson JB; J Neurochem. 1993;61:756-759. PMID:8336151