OBJECTIVE: ZAKI-4 was identified as a thyroid hormone-responsive gene in cultured human fibroblasts. A single ZAKI-4 gene encodes two isoforms, ZAKI-4 alpha and beta, both inhibiting calcineurin activity. ZAKI-4 alpha and beta differ at their N termini, and show distinct distribution profiles in human tissues. The aim of this study was to elucidate the organization of the mouse ZAKI-4 gene and to determine the effect of thyroid hormone on the expression of ZAKI-4 isoforms in vivo. DESIGN: We cloned mouse homologues of human ZAKI-4 alpha and beta cDNA. Fluorescence in situ hybridization and bioinformatics analysis were employed to determine the gene organization. The effect of thyroid hormone on the expression of ZAKI-4 isoforms in mouse brain and heart was also studied. METHODS: Total RNA extracted from mouse cerebellum was used to clone ZAKI-4 alpha and beta cDNAs by RT-PCR followed by rapid amplification of cDNA ends. Mice were rendered hypothyroid by feeding a low iodine diet supplemented with propylthiouracil for 2 weeks. In one group (hyperthyroid) L-T(3) was injected i.p. for the last 4 days whereas another group (hypothyroid) received vehicle only. Non-treated mice were controls. RESULTS AND CONCLUSION: Mouse ZAKI-4 alpha and beta cDNAs were highly homologous to the human isoforms. The gene was mapped on chromosome 17qC, syntenic to human chromosome 6 where the human ZAKI-4 gene is located. As observed in human, ZAKI-4 alpha mRNA was expressed only in brain whereas beta mRNA was distributed in other tissues as well, such as heart and skeletal muscle. ZAKI-4 alpha mRNA was lower in the cerebral cortex of hypothyroid mice. Injection of L-T(3) caused an increase in ZAKI-4 beta mRNA in heart; however, expression of neither ZAKI-4 alpha nor beta mRNA was influenced by thyroid status in other tissues. These results indicate that expression of ZAKI-4 alpha and beta isoforms is regulated by thyroid hormone in vivo, and the regulation is isoform- and tissue-specific.
OBJECTIVE:ZAKI-4 was identified as a thyroid hormone-responsive gene in cultured human fibroblasts. A single ZAKI-4 gene encodes two isoforms, ZAKI-4 alpha and beta, both inhibiting calcineurin activity. ZAKI-4 alpha and beta differ at their N termini, and show distinct distribution profiles in human tissues. The aim of this study was to elucidate the organization of the mouseZAKI-4 gene and to determine the effect of thyroid hormone on the expression of ZAKI-4 isoforms in vivo. DESIGN: We cloned mouse homologues of humanZAKI-4 alpha and beta cDNA. Fluorescence in situ hybridization and bioinformatics analysis were employed to determine the gene organization. The effect of thyroid hormone on the expression of ZAKI-4 isoforms in mouse brain and heart was also studied. METHODS: Total RNA extracted from mouse cerebellum was used to clone ZAKI-4 alpha and beta cDNAs by RT-PCR followed by rapid amplification of cDNA ends. Mice were rendered hypothyroid by feeding a low iodine diet supplemented with propylthiouracil for 2 weeks. In one group (hyperthyroid) L-T(3) was injected i.p. for the last 4 days whereas another group (hypothyroid) received vehicle only. Non-treated mice were controls. RESULTS AND CONCLUSION:MouseZAKI-4 alpha and beta cDNAs were highly homologous to the human isoforms. The gene was mapped on chromosome 17qC, syntenic to human chromosome 6 where the humanZAKI-4 gene is located. As observed in human, ZAKI-4 alpha mRNA was expressed only in brain whereas beta mRNA was distributed in other tissues as well, such as heart and skeletal muscle. ZAKI-4 alpha mRNA was lower in the cerebral cortex of hypothyroidmice. Injection of L-T(3) caused an increase in ZAKI-4 beta mRNA in heart; however, expression of neither ZAKI-4 alpha nor beta mRNA was influenced by thyroid status in other tissues. These results indicate that expression of ZAKI-4 alpha and beta isoforms is regulated by thyroid hormone in vivo, and the regulation is isoform- and tissue-specific.
Authors: Young Joo Park; Eun Kyung Lee; Yoon Kwang Lee; Do Joon Park; Hak Chul Jang; David D Moore Journal: Toxicol Appl Pharmacol Date: 2012-04-03 Impact factor: 4.219
Authors: Jae Hoon Moon; Hyung Jun Kim; Hyun Min Kim; Sung Hee Choi; Soo Lim; Young Joo Park; Hak Chul Jang; Bong Soo Cha Journal: Thyroid Date: 2013-08-28 Impact factor: 6.568