Abstract
Mammalian Sterile20-like (MST) kinases are located upstream in the mitogen-activated protein kinase pathway, and play an important role in cell proliferation, differentiation, renewal, polarization and migration. Generally, five MST kinases exist in mammalian signal transduction pathways, including MST1, MST2, MST3, MST4 and YSK1. The central nervous system (CNS) is a sophisticated entity that takes charge of information reception, integration and response. Recently, accumulating evidence proposes that MST kinases are critical in the development of disease in different systems involving the CNS. In this review, we summarized the signal transduction pathways and interacting proteins of MST kinases. The potential biological function of each MST kinase and the commonly reported MST-related diseases in the neural system are also reviewed. Further investigation of MST kinases and their interaction with CNS diseases would provide the medical community with new therapeutic targets for human diseases.
Highlights
Mitogen-activated protein kinases (MAPKs) signal cascades are highly conserved across eukaryotes and have a pivotal role in meditating cell proliferation, cell differentiation, stress-related response and cell death [1]
Sterile 20 (STE20) kinases are located upstream in the MAPK pathway in budding yeast, subsequently invoking the MAPK kinases to initiate the MAPKs [3, 4]. According to their distinct structures and functions, STE20 kinases can be broadly divided into two subfamilies, p21Rac/Cdc42-activated kinases (PAKs) [5] and germinal center kinases (GCKs) [6]
As the mammalian homologues of STE20, Mammalian Sterile20-like (MST) kinases considered as a part of the GCK subfamily [7]
Summary
There are five MST kinases including MST1 or serine/threonine-protein kinase 4 (STK4), MST2 (STK3), MST3 (STK24), MST4 (STK26), and YSK1 (STK25). The biological functions of these kinases include their roles in signal transduction pathways which help maintain cell homeostasis We introduced these kinases in two parts: MST1 and MST2 (Fig. 1); MST3, MST4 and YSK1 (Fig. 2). The MST1-FOXO signaling pathway is beneficial for the immune system in maintaining naive T cell homeostasis [39] Another downstream protein of MST1, JNK, is activated under the induction of discharged or overexpressed MST1, which was shown to be important for chromatin condensation during apoptosis[40]. Some studies show that MST1 and MST2 have several interacting partners, including RASSF members, DAP4, acinus and Raf-1 They combine with the MST1 and MST2 and promote different biological functions in cellular signal pathway [7]. Evidence of MST4 or YSK1 directly phosphorylating NDR protein kinases in mammalian systems remains unclear [48]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
