Krebs J, Wilson A, Kisielow P
Institute of Biochemistry, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.
Biochem Biophys Res Commun. 1997 Dec 18;241(2):383-9. doi: 10.1006/bbrc.1997.7823.
In a primary cell culture system of fetal rat brain, the calmodulin-dependent protein-kinase IV (CaMKIV) could be induced by the thyroid hormone T3 in a time- and concentration-dependent manner, provided the tissue was excised not later than day 15 of gestation (E15) (Krebs et al., J. Biol. Chem. 271, 11055, 1996). We report here that in the fetal thymus CaMKIV could not be detected earlier than day 16 of gestation and that the expression of this enzyme was fully upregulated at day 18. In mouse fetal thymus organ culture (FTOC) of day 14 embryonic thymus, CaMKIV could not be detected, even after several days of culture if a minimal culture medium lacking fetal calf serum was used. However, after addition of fetal calf serum to the culture medium the expression of CaMKIV could be specifically induced. Furthermore, it could also be shown that during T-cell development in the adult murine thymus the expression of CaMKIV was tightly regulated. Taken together, these results demonstrate that the expression of CaMKIV, an enzyme involved in the regulation of Ca(2+)-dependent gene expression, is itself under stringent regulatory control during tissue development.
在胎鼠脑原代细胞培养系统中，只要组织在妊娠第15天（E15）之前切除，甲状腺激素T3就能以时间和浓度依赖的方式诱导钙调蛋白依赖性蛋白激酶IV（CaMKIV）（Krebs等人，《生物化学杂志》271, 11055, 1996）。我们在此报告，在胎鼠胸腺中，直到妊娠第16天才能检测到CaMKIV，且该酶的表达在第18天完全上调。在第14天胚胎胸腺的小鼠胎胸腺器官培养（FTOC）中，即使使用不含胎牛血清的基础培养基培养数天，也检测不到CaMKIV。然而，向培养基中添加胎牛血清后，CaMKIV的表达可被特异性诱导。此外，还可以证明，在成年小鼠胸腺的T细胞发育过程中，CaMKIV的表达受到严格调控。综上所述，这些结果表明，参与钙（2+）依赖性基因表达调控的酶CaMKIV的表达，在组织发育过程中本身也受到严格的调控。
