Serine/threonine-protein kinase 4 (EC 2.7.11.1) (Mammalian STE20-like protein kinase 1) (MST-1) (STE20-like kinase MST1) (Serine/threonine-protein kinase Krs-2) [Cleaved into: Serine/threonine-protein kinase 4 37kDa subunit (MST1/N); Serine/threonine-protein kinase 4 18kDa subunit (MST1/C)]
1_METVQ 6_ LRNPP 11_ RRQLK 16_ KLDED 21_ SLTKQ 26_ PEEVF 31_ DVLEK 36_ LGEGS 41_ YGSVY 46_ KAIHK 51_ ETGQI 56_ VAIKQ 61_ VPVES 66_ DLQEI 71_ IKEIS 76_ IMQQC 81_ DSPHV 86_ VKYYG 91_ SYFKN 96_ TDLWI 101_ VMEYC 106_ GAGSV 111_ SDIIR 116_ LRNKT 121_ LTEDE 126_ IATIL 131_ QSTLK 136_ GLEYL 141_ HFMRK 146_ IHRDI 151_ KAGNI 156_ LLNTE 161_ GHAKL 166_ ADFGV 171_ AGQLT 176_ DTMAK 181_ RNTVI 186_ GTPFW 191_ MAPEV 196_ IQEIG 201_ YNCVA 206_ DIWSL 211_ GITAI 216_ EMAEG 221_ KPPYA 226_ DIHPM 231_ RAIFM 236_ IPTNP 241_ PPTFR 246_ KPELW 251_ SDNFT 256_ DFVKQ 261_ CLVKS 266_ PEQRA 271_ TATQL 276_ LQHPF 281_ VRSAK 286_ GVSIL 291_ RDLIN 296_ EAMDV 301_ KLKRQ 306_ ESQQR 311_ EVDQD 316_ DEENS 321_ EEDEM 326_ DSGTM 331_ VRAVG 336_ DEMGT 341_ VRVAS 346_ TMTDG 351_ ANTMI 356_ EHDDT 361_ LPSQL 366_ GTMVI 371_ NAEDE 376_ EEEGT 381_ MKRRD 386_ ETMQP 391_ AKPSF 396_ LEYFE 401_ QKEKE 406_ NQINS 411_ FGKSV 416_ PGPLK 421_ NSSDW 426_ KIPQD 431_ GDYEF 436_ LKSWT 441_ VEDLQ 446_ KRLLA 451_ LDPMM 456_ EQEIE 461_ EIRQK 466_ YQSKR 471_ QPILD 476_ AIEAK 481_KRRQQ
1: Stress-activated, pro-apoptotic kinase which, following caspase-cleavage, enters the nucleus and induces chromatin condensation followed by internucleosomal DNA fragmentation. Key component of 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 LATS2 inhibits its translocation into the nucleus to regulate cellular genes important for cell proliferation, cell death, and cell migration. STK3/MST2 and STK4/MST1 are required to repress proliferation of mature hepatocytes, to prevent activation of facultative adult liver stem cells (oval cells), and to inhibit tumor formation (By similarity). Phosphorylates 'Ser-14' of histone H2B (H2BS14ph) during apoptosis. Phosphorylates FOXO3 upon oxidative stress, which results in its nuclear translocation and cell death initiation. Phosphorylates MOBKL1A, MOBKL1B and RASSF2. Phosphorylates TNNI3 (cardiac Tn-I) and alters its binding affinity to TNNC1 (cardiac Tn-C) and TNNT2 (cardiac Tn-T). Phosphorylates FOXO1 on 'Ser-212' and regulates its activation and stimulates transcription of PMAIP1 in a FOXO1-dependent manner. Phosphorylates SIRT1 and inhibits SIRT1-mediated p53/TP53 deacetylation, thereby promoting p53/TP53 dependent transcription and apoptosis upon DNA damage. Acts as an inhibitor of PKB/AKT1. Phosphorylates AR on 'Ser-650' and suppresses its activity by intersecting with PKB/AKT1 signaling and antagonizing formation of AR-chromatin complexes