Alternative titles; symbols
HGNC Approved Gene Symbol: HIC2
Cytogenetic location: 22q11.21 Genomic coordinates (GRCh38) : 22:21,417,371-21,451,463 (from NCBI)
By sequencing clones obtained from a size-fractionated fetal brain cDNA library, Kikuno et al. (1999) cloned HIC2, which they designated KIAA1020. RT-PCR ELISA revealed highest expression in cerebellum, with intermediate levels in several other brain regions; no expression was detected in substantia nigra. In whole tissues, expression was highest in liver, followed by heart, brain, lung, kidney, testis, ovary, fetal liver, and fetal brain. Little or no expression was detected in skeletal muscle, pancreas, and spleen.
Deltour et al. (2001) extended the sequence of KIAA1020 in the 5-prime direction by comparison with a genomic clone and by RT-PCR of a cerebellum cDNA library. The deduced full-length HIC2 protein contains 615 amino acids. It has an N-terminal BTB/POZ domain, a conserved GLDLSKK/R polypeptide, and 5 C-terminal Kruppel-type C2H2 fingers, 4 of which are grouped and are separated by a typical 7- to 8-amino acid link. HIC2 shares more than 80% homology with HIC1 (603825) through the BTB/POZ and zinc finger domains, and both proteins have identical GLDLSKK/R motifs.
By transient transfection in COS-7 cells, Deltour et al. (2001) found that HIC2 colocalized with HIC1 onto nuclear dots. Their BTB/POZ domains heterodimerized and repressed transcription from a reporter plasmid. Inhibitor studies indicated that HIC1 and HIC2 do not recruit HDAC (see 601241)-containing complexes. The central GLDLSKK/R motif was found to interact with C-terminal-binding protein (see 602618).
Deltour et al. (2001) determined that the HIC2 gene contains 2 exons and spans about 6.1 kb. The promoter region contains a putative TATA box.
By genomic sequence analysis, Deltour et al. (2001) mapped the HIC2 gene to chromosome 22q11.2.
Deltour, S., Pinte, S., Guerardel, C., Leprince, D. Characterization of HRG22, a human homologue of the putative tumor suppressor gene HIC1. Biochem. Biophys. Res. Commun. 287: 427-434, 2001. [PubMed: 11554746] [Full Text: https://doi.org/10.1006/bbrc.2001.5624]
Kikuno, R., Nagase, T., Ishikawa, K., Hirosawa, M., Miyajima, N., Tanaka, A., Kotani, H., Nomura, N., Ohara, O. Prediction of the coding sequences of unidentified human genes. XIV. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro. DNA Res. 6: 197-205, 1999. [PubMed: 10470851] [Full Text: https://doi.org/10.1093/dnares/6.3.197]