6mcp
From Proteopedia
L. pneumophila effector kinase LegK7 (AMP-PNP bound) in complex with human MOB1A
Structural highlights
Function[MOB1A_HUMAN] Activator of LATS1/2 in the Hippo signaling pathway which plays a pivotal role in organ size control and tumor suppression by restricting proliferation and promoting apoptosis. The core of this pathway is composed of a kinase cascade wherein STK3/MST2 and STK4/MST1, in complex with its regulatory protein SAV1, phosphorylates and activates LATS1/2 in complex with its regulatory protein MOB1, which in turn phosphorylates and inactivates YAP1 oncoprotein and WWTR1/TAZ. Phosphorylation of YAP1 by LATS1/2 inhibits its translocation into the nucleus to regulate cellular genes important for cell proliferation, cell death, and cell migration. Stimulates the kinase activity of STK38 and STK38L. Acts cooperatively with STK3/MST2 to activate STK38.[1] [2] [3] Publication Abstract from PubMedDuring infection, the bacterial pathogen Legionella pneumophila manipulates a variety of host cell signaling pathways, including the Hippo pathway which controls cell proliferation and differentiation in eukaryotes. Our previous studies revealed that L. pneumophila encodes the effector kinase LegK7 which phosphorylates MOB1A, a highly conserved scaffold protein of the Hippo pathway. Here, we show that MOB1A, in addition to being a substrate of LegK7, also functions as an allosteric activator of its kinase activity. A crystallographic analysis of the LegK7-MOB1A complex revealed that the N-terminal half of LegK7 is structurally similar to eukaryotic protein kinases, and that MOB1A directly binds to the LegK7 kinase domain. Substitution of interface residues critical for complex formation abrogated allosteric activation of LegK7 both in vitro and within cells and diminished MOB1A phosphorylation. Importantly, the N-terminal extension (NTE) of MOB1A not only regulated complex formation with LegK7 but also served as a docking site for downstream substrates such as the transcriptional coregulator YAP1. Deletion of the NTE from MOB1A or addition of NTE peptides as binding competitors attenuated YAP1 recruitment to and phosphorylation by LegK7. By providing mechanistic insight into the formation and regulation of the LegK7-MOB1A complex, our study unravels a sophisticated molecular mimicry strategy that is used by L. pneumophila to take control of the host cell Hippo pathway. The Legionella kinase LegK7 exploits the Hippo pathway scaffold protein MOB1A for allostery and substrate phosphorylation.,Lee PC, Beyrakhova K, Xu C, Boniecki MT, Lee MH, Onu CJ, Grishin AM, Machner MP, Cygler M Proc Natl Acad Sci U S A. 2020 Jun 23;117(25):14433-14443. doi:, 10.1073/pnas.2000497117. Epub 2020 Jun 8. PMID:32513747[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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