Radrizzani M, Carminatti H, Pivetta O H, Idoyaga Vargas V P
Instituto de investigaciones Bioquímicas Fundación Campomar, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina.
J Neurosci Res. 1995 Oct 1;42(2):220-7. doi: 10.1002/jnr.490420209.
Thy 1.2 is a well-known major cell surface glycoprotein of the central nervous system (CNS). However, the regulation of the expression of this molecule as well as its function are yet to be determined. To approach these problems we studied the synthesis of the molecule in the developing cerebellum of wild-type and staggerer mutant mice. We found the appearance of a [35S]-methionine-labeled band detected with specific Sepharose 4B-bound monoclonal antibodies (Mabs). The Thy 1.2 activity increases progressively from postnatal day 9 (P9), reaching the highest rate at P12, subsequently decreasing sharply at P13, and remaining relatively low up to P16 in the wild type. Comparison of these data to the rates of total protein synthesis reveals a selective developmental regulation of Thy 1.2 expression, at least at the translational level. This correlates quite well with the timing of synaptic stabilization between parallel fibers and Purkinje cell dendritic spines. Furthermore, at P12 Thy 1.2 protein is preferentially located in the synaptosomal fraction. The parallel fiber:Purkinje cell synapsis is not stabilized in the staggerer mutant mouse. At P12 Thy 1.2 synthesis is 30% of the wild type, indicating that the translational regulation of Thy 1.2 is altered in the staggerer mutation.
Thy 1.2是中枢神经系统（CNS）一种著名的主要细胞表面糖蛋白。然而，该分子表达的调控及其功能尚未确定。为了解决这些问题，我们研究了野生型和蹒跚突变型小鼠发育中小脑内该分子的合成情况。我们发现用特异性结合琼脂糖4B的单克隆抗体（Mab）检测到一条[35S] - 甲硫氨酸标记的条带。在野生型中，Thy 1.2活性从出生后第9天（P9）开始逐渐增加，在P12达到最高速率，随后在P13急剧下降，并在P16之前一直保持相对较低水平。将这些数据与总蛋白合成速率进行比较，发现Thy 1.2表达存在选择性发育调控，至少在翻译水平上如此。这与平行纤维和浦肯野细胞树突棘之间突触稳定的时间相当吻合。此外，在P12时，Thy 1.2蛋白优先位于突触体部分。在蹒跚突变型小鼠中，平行纤维：浦肯野细胞突触不稳定。在P12时，Thy 1.2的合成是野生型的30%，表明在蹒跚突变中Thy 1.2的翻译调控发生了改变。
