Almasan A, Mangelsdorf D J, Ong E S, Wahl G M, Evans R M
Salk Institute for Biological Studies, La Jolla, California 92037.
Genomics. 1994 Apr;20(3):397-403. doi: 10.1006/geno.1994.1193.
The recently described retinoid X receptors (RXRs) respond to the novel retinoid 9-cis-retinoic acid and also serve as heterodimeric partners for the vitamin D, thyroid hormone, and retinoic acid receptors (VDR, TR, and RAR, respectively). In this work, we report high-resolution localization of the human RXR genes within cytogenetic bands and also within a standard reference map of cosmid DNA markers on human chromosomes. We have determined the location of the human RXR genes by pairwise hybridization of the RXR cosmids and reference markers, using fluorescence in situ hybridization. We localized (i) RXR alpha (RXRA) to chromosome 9 band q34.3; (ii) RXR beta (RXRB) to chromosome 6 band 21.3; and (iii) RXR gamma (RXRG) to chromosome 1 band q22-q23. Six retinoid-responsive transcription factors have been identified so far, including three retinoic acid receptors in addition to the three RXRs. Interestingly, each of these receptors in human and mouse is encoded by genes located at distinct chromosomal loci and on separate chromosomes. The proximity of RXR genes to loci known to be associated with genetic disorders suggests that their location may be useful in establishing a link between RXRs and certain human diseases.
最近发现的类视黄醇X受体（RXRs）对新型类视黄醇9-顺式视黄酸有反应，并且还作为维生素D、甲状腺激素和视黄酸受体（分别为VDR、TR和RAR）的异二聚体伴侣。在这项研究中，我们报告了人类RXR基因在细胞遗传学带内以及人类染色体上粘粒DNA标记的标准参考图谱中的高分辨率定位。我们通过使用荧光原位杂交技术，将RXR粘粒与参考标记进行成对杂交，确定了人类RXR基因的位置。我们将（i）RXRα（RXRA）定位到9号染色体q34.3带；（ii）RXRβ（RXRB）定位到6号染色体21.3带；（iii）RXRγ（RXRG）定位到1号染色体q22 - q23带。到目前为止，已经鉴定出六种类视黄醇反应性转录因子，除了三种RXRs之外，还包括三种视黄酸受体。有趣的是，人类和小鼠中的每种受体都由位于不同染色体位点和不同染色体上的基因编码。RXR基因与已知与遗传疾病相关的位点的接近性表明，它们的位置可能有助于建立RXRs与某些人类疾病之间的联系。
