Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, 04510, Mexico.
Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, 04510, Mexico.
Plant Sci. 2020 Feb;291:110330. doi: 10.1016/j.plantsci.2019.110330. Epub 2019 Nov 6.
The AMPK/SNF1/SnRK1 family of protein kinases is involved in cellular responses to energy stress. They also interact with molecules of other signaling pathways to regulate many aspects of growth and development. The biochemical, genetic and molecular knowledge of SnRK1 in plants lags behind that of AMPK and SNF1 and is freely extrapolated such that, in many cases, it is assumed that plant enzymes behave in the same way as homologs in other organisms. In this review, we present data that support the evidence that the structural characteristics of the SnRK1 subunits determine the functional properties of the complex. We also discuss results suggesting that the SnRK1 subunits participate in the assembly of different complexes and that not all combinations are equally important. The activity of SnRK1 is dependent on the phosphorylation of SnRK1α found in the activation loop of the catalytic domain. However, we propose that the phosphorylation of sites close to SnRK1α might contribute to the fine-tuned regulation of SnRK1 activity and thus requires further evaluation. Finally, we also call attention to the interaction of the SnRK1α with regulatory proteins that are not typically identified as putative substrates. The additional functions of the SnRK1 subunits, in addition to those of the active complex, may be necessary for the cell to respond to the complicated conditions presented by energy stress.
AMPK/SNF1/SnRK1 蛋白激酶家族参与细胞对能量应激的反应。它们还与其他信号通路的分子相互作用，调节生长和发育的许多方面。植物中 SnRK1 的生化、遗传和分子知识落后于 AMPK 和 SNF1，并且可以自由推断，在许多情况下，假设植物酶的行为与其他生物体中的同源物相同。在这篇综述中，我们提供了支持以下证据的数据：SnRK1 亚基的结构特征决定了复合物的功能特性。我们还讨论了表明 SnRK1 亚基参与不同复合物组装的结果，并且并非所有组合都同等重要。SnRK1 的活性依赖于在催化结构域的激活环中发现的 SnRK1α 的磷酸化。然而，我们提出靠近 SnRK1α 的磷酸化位点的磷酸化可能有助于对 SnRK1 活性的精细调节，因此需要进一步评估。最后，我们还提请注意 SnRK1α 与通常不作为假定底物鉴定的调节蛋白的相互作用。除了活性复合物之外，SnRK1 亚基的其他功能可能对于细胞响应能量应激所呈现的复杂条件是必需的。
