Dan I, Watanabe N M, Kusumi A
Department of Biological Science, Nagoya University, Chikusa-ku, 464-8602, Nagoya, Japan.
Trends Cell Biol. 2001 May;11(5):220-30. doi: 10.1016/s0962-8924(01)01980-8.
Ste20p (sterile 20 protein) is a putative yeast mitogen-activated protein kinase kinase kinase kinase (MAP4K) involved in the mating pathway. Its homologs in mammals, Drosophila, Caenorhabditis elegans and other organisms make up a large emerging group of protein kinases including 28 members in human. The Ste20 group kinases are further divided into the p21-activated kinase (PAK) and germinal center kinase (GCK) families. They are characterized by the presence of a conserved kinase domain and a noncatalytic region of great structural diversity that enables the kinases to interact with various signaling molecules and regulatory proteins of the cytoskeleton. This review describes the phylogenetic relationships of the Ste20 group kinases based on discussions with many researchers in this field. With the newly established phylogenetic relationships, crucial arguments can be advanced regarding the functions of these kinases as upstream activators of the MAPK pathways and possible activity as MAP4Ks. Their involvement in apoptosis, morphogenesis and cytoskeletal rearrangements is also discussed.
Ste20p（无菌20蛋白）是一种推定的酵母丝裂原活化蛋白激酶激酶激酶激酶（MAP4K），参与交配途径。它在哺乳动物、果蝇、秀丽隐杆线虫和其他生物体中的同源物构成了一个新兴的蛋白激酶大组，其中人类有28个成员。Ste20组激酶进一步分为p21活化激酶（PAK）和生发中心激酶（GCK）家族。它们的特征是存在一个保守的激酶结构域和一个结构高度多样的非催化区域，这使得这些激酶能够与细胞骨架的各种信号分子和调节蛋白相互作用。本综述基于与该领域众多研究人员的讨论，描述了Ste20组激酶的系统发育关系。基于新建立的系统发育关系，可以就这些激酶作为MAPK途径上游激活剂的功能以及作为MAP4Ks的可能活性提出关键论点。还讨论了它们在细胞凋亡、形态发生和细胞骨架重排中的作用。
