Format

Send to

Choose Destination

See 1 citation found by title matching your search:

J Biol Chem. 2018 Apr 13;293(15):5532-5543. doi: 10.1074/jbc.RA117.000923. Epub 2018 Mar 8.

Salvador has an extended SARAH domain that mediates binding to Hippo kinase.

Author information

1
From the Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 20215.
2
the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, and.
3
From the Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 20215, jkavran@jhu.edu.
4
the Departments of Biophysics and Biophysical Chemistry, School of Medicine, and.
5
Oncology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 20215.

Abstract

The Hippo pathway controls cell proliferation and differentiation through the precisely tuned activity of a core kinase cassette. The activity of Hippo kinase is modulated by interactions between its C-terminal coiled-coil, termed the SARAH domain, and the SARAH domains of either dRassF or Salvador. Here, we wanted to understand the molecular basis of SARAH domain-mediated interactions and their influence on Hippo kinase activity. We focused on Salvador, a positive effector of Hippo activity and the least well-characterized SARAH domain-containing protein. We determined the crystal structure of a complex between Salvador and Hippo SARAH domains from Drosophila This structure provided insight into the organization of the Salvador SARAH domain including a folded N-terminal extension that expands the binding interface with Hippo SARAH domain. We also found that this extension improves the solubility of the Salvador SARAH domain, enhances binding to Hippo, and is unique to Salvador. We therefore suggest expanding the definition of the Salvador SARAH domain to include this extended region. The heterodimeric assembly observed in the crystal was confirmed by cross-linked MS and provided a structural basis for the mutually exclusive interactions of Hippo with either dRassF or Salvador. Of note, Salvador influenced the kinase activity of Mst2, the mammalian Hippo homolog. In co-transfected HEK293T cells, human Salvador increased the levels of Mst2 autophosphorylation and Mst2-mediated phosphorylation of select substrates, whereas Salvador SARAH domain inhibited Mst2 autophosphorylation in vitro These results suggest Salvador enhances the effects of Hippo kinase activity at multiple points in the Hippo pathway.

KEYWORDS:

Hippo pathway; Salvador (sav); cell signaling; crystal structure; enzyme; protein phosphorylation; structure-function

PMID:
29519817
PMCID:
PMC5900767
[Available on 2019-04-13]
DOI:
10.1074/jbc.RA117.000923
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center