Structure and transcriptional regulation of gene encoding human FK506 binding protein 12 and 12.6

环ADP-核糖（cADPR）诱导胰岛微粒体释放Ca^2+以分泌胰岛素。已经证明cADPR与大鼠胰岛兰尼碱受体上的FK 506结合蛋白（FKBP）结合，并且cADPR与FKBP的结合使兰尼碱受体从FKBP中释放出来，导致其释放Ca^2+（J. Biol. Chem. 272，3133，1997）。本研究分离了人FKBP 12.6和FKBP 12基因，并对其结构和染色体定位进行了研究.人FKBP 12.6基因全长约16 kbp。FKBP 12.6基因由4个外显子和3个内含子组成。人FKBP 12基因全长约20 kbp。FKBP 12基因由5个外显子和4个内含子组成。FKBP12.6和FKBP 12基因的外显子-内含子连接位置完全匹配，除了FKBP 12有一个额外的外显子5，专门编码3 '-非翻译区。荧光原位杂交结果显示FKBP 12.6基因定位于染色体2 p21 ...更多信息 FKBP 12基因定位于染色体20 p13。其次，我们利用荧光素酶分析法对人FKBP 12. 6和FKBP 12基因的启动子区进行了分析。将人FKBP 12.6基因-1691位点的一系列5 '-缺失和FKBP 12基因-1706位点的一系列5'-缺失转染NB-1细胞进行荧光素酶检测.缺失-1691 ~+8序列对荧光素酶表达无明显影响。进一步删除到+74导致表达的显著丢失。这些结果表明+8的74序列对于人FKBP 12.6基因的表达具有重要意义.缺失-1706 ~-179序列对荧光素酶表达无明显影响。进一步删除到-74导致表达的显著损失。将-179-74序列反向插入到-179-74缺失报告质粒中，并插入到-179-74缺失报告质粒的荧光素酶基因的3 '端，恢复了表达。这些结果表明，-179bp-74序列作为人FKBP 12基因表达的增强子。少

Cyclic ADP-ribose (cADPR) induces the release of Ca^<2+> from microsomes of pancreatic islets for insulin secretion. It has been demonstrated that cADPR binds to FK506-binding protein (FKBP) on rat islet ryanodine receptor and that the binding of cADPR to FKBP frees the ryanodine receptor from FKBP, causing it to release Ca^<2+> (J. Biol. Chem. 272, 3133, 1997). In this study, we have isolated human FKBP12.6 and FKBP 12 gene and determined their structure and chromosomal localization.1. Human FKBP12.6 gene spanned about 16 kbp in length. The FKBP12.6 gene consisted of four exons and three introns. Human FKBP 12 gene spanned about 20 kbp in length. The FKBP 12 gene consited of five exons and four introns. The positions of exon-intron junction of the FKBP12.6 and FKBP12 genes were perfectly matched except that FKBP12 has an additional exon 5, to code exclusively for 3'-untranslated region.2. Fluorescence in situ hybridization revealed that the FKBP12.6 gene was located on chromosome 2p21 … More -23 and the FKBP12 gene was located on chromosome 20p13.Next, we analyzed the promoter regions of human FKBP12.6 and FKBP 12 genes with luciferase assay.3. A series of 5'-deletions from -1691 of human FKBP12.6 gene and a series of 5'-deletions from -1706 of FKBP 12 gene were transfected into NB-1 cells for luciferase assay.4. Deletion of the sequence from -1691 to +8 caused no significant changes of the expression of luciferase. Further deletion to +74 caused a marked loss of the expression. These results suggest the importance of +8〜+74 sequence for the expression of the human FKBP 12.6 gene.5. Deletion of the sequence from -1706 to -179 caused no significant changes of the expression of luciferase. Further deletion to -74 caused a marked loss of the expression. Insertion of -179〜-74 sequence into -179〜-74 deleted reporter plasmid with reverse orientation and insertion into 3'-portion of the luciferase gene in -179〜-74 deleted reporter plasmid recovered the expression. These results suggest that -179〜-74 sequence acts as an enhancer for the expression of the human FKBP 12 gene. Less