Brown G C, Kholodenko B N
Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambrigde, UK.
FEBS Lett. 1999 Sep 3;457(3):452-4. doi: 10.1016/s0014-5793(99)01058-3.
If a protein is rapidly phosphorylated and dephosphorylated at separate cellular locations and protein diffusion is slow, then a spatial gradient of the phosphorylated form of the protein may develop within the cell. We have estimated the potential size of such gradients using measured values of protein diffusion coefficients and protein kinase and phosphatase activities. We analysed two different cellular geometries: (1) where the kinases is located on the plasma membrane of a spherical cell and the phospatase is distributed homogenously in the cytoplasm and (2) where the kinase is located on one planar membrane and the phosphatase on a second parallel planar membrane. The estimated gradients of phospho-proteins were potentially very large, which has important implications for cellular signalling.
如果一种蛋白质在细胞内不同位置迅速发生磷酸化和去磷酸化，且蛋白质扩散缓慢，那么该蛋白质磷酸化形式可能会在细胞内形成空间梯度。我们利用蛋白质扩散系数以及蛋白激酶和磷酸酶活性的测量值估算了这种梯度的潜在大小。我们分析了两种不同的细胞几何结构：（1）激酶位于球形细胞的质膜上，磷酸酶均匀分布于细胞质中；（2）激酶位于一个平面膜上，磷酸酶位于第二个平行平面膜上。磷酸化蛋白的估算梯度可能非常大，这对细胞信号传导具有重要意义。
