serine/threonine protein kinase 4; mammalian STE20-like protein kinase 1; MST-1; STE20-like kinase MST1; serine/threonine protein kinase Krs-2 (STK4 MST1)

Function

• stress-activated, pro-apoptotic kinase
• following caspase-cleavage, enters the nucleus & induces chromatin condensation followed by internucleosomal DNA fragmentation
• component of the Hippo signaling pathway
• phosphorylates Ser-14 of histone H2B (H2BS14ph) during apoptosis
• phosphorylates FOXO3 upon oxidative stress, which results in its nuclear translocation & cell death initiation
• inhibited by the C-terminal non-catalytic region
• activated by caspase-cleavage
• full activation also requires homodimerization & autophosphorylation of Thr-183
• autophosphorylated on Ser & Thr
• interacts with NORE1, which inhibits autoactivation
• interacts with & stabilizes SAV1
• interacts with RASSF1, which leads to enzyme activation

Cofactor: Mg+2

Structure

• homodimer mediated via the coiled-coil region
• belongs to the protein kinase superfamily, STE Ser/Thr protein kinase family, STE20 subfamily
• contains 1 protein kinase domain
• contains 1 SARAH domain

Compartment

• cytoplasm, nucleus
• the caspase-cleaved form cycles between the nucleus & cytoplasm

Alternative splicing

named isoforms=2

Expression

ubiquitously expressed

More general terms

• serine/threonine kinase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=6789
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:6789
• OMIM: https://mirror.omim.org/entry/604965
• UniProt: http://www.uniprot.org/uniprot/Q13043.html