Serine/threonine-protein kinase STK11 (EC 2.7.11.1) (Liver kinase B1) (LKB1) (hLKB1) (Renal carcinoma antigen NY-REN-19)
1_MEVVD 6_ PQQLG 11_ MFTEG 16_ ELMSV 21_ GMDTF 26_ IHRID 31_ STEVI 36_ YQPRR 41_ KRAKL 46_ IGKYL 51_ MGDLL 56_ GEGSY 61_ GKVKE 66_ VLDSE 71_ TLCRR 76_ AVKIL 81_ KKKKL 86_ RRIPN 91_ GEANV 96_ KKEIQ 101_ LLRRL 106_ RHKNV 111_ IQLVD 116_ VLYNE 121_ EKQKM 126_ YMVME 131_ YCVCG 136_ MQEML 141_ DSVPE 146_ KRFPV 151_ CQAHG 156_ YFCQL 161_ IDGLE 166_ YLHSQ 171_ GIVHK 176_ DIKPG 181_ NLLLT 186_ TGGTL 191_ KISDL 196_ GVAEA 201_ LHPFA 206_ ADDTC 211_ RTSQG 216_ SPAFQ 221_ PPEIA 226_ NGLDT 231_ FSGFK 236_ VDIWS 241_ AGVTL 246_ YNITT 251_ GLYPF 256_ EGDNI 261_ YKLFE 266_ NIGKG 271_ SYAIP 276_ GDCGP 281_ PLSDL 286_ LKGML 291_ EYEPA 296_ KRFSI 301_ RQIRQ 306_ HSWFR 311_ KKHPP 316_ AEAPV 321_ PIPPS 326_ PDTKD 331_ RWRSM 336_ TVVPY 341_ LEDLH 346_ GADED 351_ EDLFD 356_ IEDDI 361_ IYTQD 366_ FTVPG 371_ QVPEE 376_ EASHN 381_ GQRRG 386_ LPKAV 391_ CMNGT 396_ EAAQL 401_ STKSR 406_ AEGRA 411_ PNPAR 416_ KACSA 421_ SSKIR 426_RLSAC
1: Tumor suppressor serine/threonine-protein kinase that controls the activity of AMP-activated protein kinase (AMPK) family members, thereby playing a role in various processes such as cell metabolism, cell polarity, apoptosis and DNA damage response. Acts by phosphorylating the T-loop of AMPK family proteins, thus promoting their activity: phosphorylates PRKAA1, PRKAA2, BRSK1, BRSK2, MARK1, MARK2, MARK3, MARK4, NUAK1, NUAK2, SIK1, SIK2, SIK3 and SNRK but not MELK. Also phosphorylates non-AMPK family proteins such as STRADA, PTEN and possibly p53/TP53. Acts as a key upstream regulator of AMPK by mediating phosphorylation and activation of AMPK catalytic subunits PRKAA1 and PRKAA2 and thereby regulates processes including: inhibition of signaling pathways that promote cell growth and proliferation when energy levels are low, glucose homeostasis in liver, activation of autophagy when cells undergo nutrient deprivation, and B-cell differentiation in the germinal center in response to DNA damage. Also acts as a regulator of cellular polarity by remodeling the actin cytoskeleton. Required for cortical neuron polarization by mediating phosphorylation and activation of BRSK1 and BRSK2, leading to axon initiation and specification. Involved in DNA damage response: interacts with p53/TP53 and recruited to the CDKN1A/WAF1 promoter to participate in transcription activation. Able to phosphorylate p53/TP53; the relevance of such result in vivo is however unclear and phosphorylation may be indirect and mediated by downstream STK11/LKB1 kinase NUAK1. Also acts as a mediator of p53/TP53-dependent apoptosis via interaction with p53/TP53: translocates to the mitochondrion during apoptosis and regulates p53/TP53-dependent apoptosis pathways. Regulates UV radiation-induced DNA damage response mediated by CDKN1A. In association with NUAK1, phosphorylates CDKN1A in response to UV radiation and contributes to its degradation which is necessary for optimal DNA repair (PubMed:25329316)
2: Has a role in spermiogenesis