Alternative titles; symbols
HGNC Approved Gene Symbol: LGI2
Cytogenetic location: 4p15.2 Genomic coordinates (GRCh38) : 4:24,992,081-25,030,946 (from NCBI)
By sequencing clones obtained from a size-fractionated adult brain cDNA library, Nagase et al. (2001) cloned LGI2, which they called KIAA1916. The deduced 542-amino acid protein shares 58% identity with LGI1 (604619). RT-PCR ELISA detected highest expression of LGI2 in heart, lung, kidney, and ovary, intermediate expression in liver and pancreas, low expression in brain and spleen, and little to no expression in skeletal muscle, testis, and spinal cord. Intermediate expression was detected in most specific brain regions examined.
By searching an EST database for sequences similar to LGI1, followed by RT-PCR, Gu et al. (2002) cloned LGI2. The deduced 545-amino acid protein contains an N-terminal signal peptide, a putative transmembrane region, and 1 partial and 4 complete leucine-rich repeats (LRRs). The LRRs are flanked on both sides by cysteine-rich regions, and the N-terminal cysteine-rich region contains a motif conserved in LGIs. LGI2 shares significant similarity with LGI1, LGI3 (608302), and LGI4 (608303). Semiquantitative PCR detected LGI2 expression only in brain, heart, and placenta.
By in situ hybridization of adult mouse brain, Senechal et al. (2005) showed that Lgi2 was expressed at low levels in most brain regions with high levels in the pyriform cortex and thalamic reticular nucleus. Lgi2 was secreted in transfected 293T cells. Immunofluorescence microscopy localized Lgi2 to discrete intracellular compartments, consistent with its presence in ER, Golgi bodies, and vesicles.
Gu et al. (2002) determined that the LGI2 gene contains 8 exons
By genomic sequence analysis, Nagase et al. (2001) mapped the LGI2 gene to chromosome 4. Gu et al. (2002) mapped the LGI2 gene to chromosome 4p15.2 by genomic sequence analysis and radiation hybrid analysis. They mapped the mouse Lgi2 gene to chromosome 5.
Gu, W., Wevers, A., Schroder, H., Grzeschik, K.-H., Derst, C., Brodtkorb, E., de Vos, R., Steinlein, O. K. The LGI1 gene involved in lateral temporal lobe epilepsy belongs to a new subfamily of leucine-rich repeat proteins. FEBS Lett. 519: 71-76, 2002. [PubMed: 12023020] [Full Text: https://doi.org/10.1016/s0014-5793(02)02713-8]
Nagase, T., Kikuno, R., Ohara, O. Prediction of the coding sequences of unidentified human genes. XXI. The complete sequences of 60 new cDNA clones from brain which code for large proteins. DNA Res. 8: 179-187, 2001. [PubMed: 11572484] [Full Text: https://doi.org/10.1093/dnares/8.4.179]
Senechal, K. R., Thaller, C., Noebels, J. L. ADPEAF mutations reduce levels of secreted LGI1, a putative tumor suppressor protein linked to epilepsy. Hum. Molec. Genet. 14: 1613-1620, 2005. [PubMed: 15857855] [Full Text: https://doi.org/10.1093/hmg/ddi169]