Humbert S, Lanier L M, Tsai L H
Howard Hughes Medical Institute and Department of Pathology, Harvard Medical School, Boston, MA 02115, USA.
Neuroreport. 2000 Jul 14;11(10):2213-6. doi: 10.1097/00001756-200007140-00030.
The expression and kinase activity of cyclin dependent kinase 5 (cdk5) parallels the extent of neuronal differentiation. Cdk5 activity has been shown to be required for neurite outgrowth, cortical lamination and the overall development of the nervous system. p35 was identified as the first regulatory activator of cdk5 whose presence is required for cdk5 activation. p39 is a homolog of p35, and the only one identified in mammals thus far. We show here that p39 expression is mainly postnatal. In addition, we provide evidence for the presence of p39 at synaptic junctions through co-fractionation experiment, electron microscopy and immunostaining. The temporal and spatial expression of p39 indicate a possible role of the p39/cdk5 kinase at the synapse.
细胞周期蛋白依赖性激酶5（cdk5）的表达和激酶活性与神经元分化程度平行。已证明cdk5活性是神经突生长、皮质分层和神经系统整体发育所必需的。p35被确定为cdk5的第一个调节激活因子，其存在是cdk5激活所必需的。p39是p35的同源物，也是迄今为止在哺乳动物中发现的唯一同源物。我们在此表明p39主要在出生后表达。此外，我们通过共分级分离实验、电子显微镜和免疫染色为突触连接处存在p39提供了证据。p39的时空表达表明p39/cdk5激酶在突触处可能发挥作用。
