Extracellular serine/threonine protein kinase FAM20C (EC 2.7.11.1) (Dentin matrix protein 4) (DMP-4) (Golgi casein kinase) (Golgi-enriched fraction casein kinase) (GEF-CK)
1_MKMML 6_ VRRFR 11_ VLILM 16_ VFLVA 21_ CALHI 26_ ALDLL 31_ PRLER 36_ RGARP 41_ SGEPG 46_ CSCAQ 51_ PAAEV 56_ AAPGW 61_ AQVRG 66_ RPGEP 71_ PAASS 76_ AAGDA 81_ GWPNK 86_ HTLRI 91_ LQDFS 96_ SDPSS 101_ NLSSH 106_ SLEKL 111_ PPAAE 116_ PAERA 121_ LRGRD 126_ PGALR 131_ PHDPA 136_ HRPLL 141_ RDPGP 146_ RRSES 151_ PPGPG 156_ GDASL 161_ LARLF 166_ EHPLY 171_ RVAVP 176_ PLTEE 181_ DVLFN 186_ VNSDT 191_ RLSPK 196_ AAENP 201_ DWPHA 206_ GAEGA 211_ EFLSP 216_ GEAAV 221_ DSYPN 226_ WLKFH 231_ IGINR 236_ YELYS 241_ RHNPA 246_ IEALL 251_ HDLSS 256_ QRITS 261_ VAMKS 266_ GGTQL 271_ KLIMT 276_ FQNYG 281_ QALFK 286_ PMKQT 291_ REQET 296_ PPDFF 301_ YFSDY 306_ ERHNA 311_ EIAAF 316_ HLDRI 321_ LDFRR 326_ VPPVA 331_ GRMVN 336_ MTKEI 341_ RDVTR 346_ DKKLW 351_ RTFFI 356_ SPANN 361_ ICFYG 366_ ECSYY 371_ CSTEH 376_ ALCGK 381_ PDQIE 386_ GSLAA 391_ FLPDL 396_ SLAKR 401_ KTWRN 406_ PWRRS 411_ YHKRK 416_ KAEWE 421_ VDPDY 426_ CEEVK 431_ QTPPY 436_ DSSHR 441_ ILDVM 446_ DMTIF 451_ DFLMG 456_ NMDRH 461_ HYETF 466_ EKFGN 471_ ETFII 476_ HLDNG 481_ RGFGK 486_ YSHDE 491_ LSILV 496_ PLQQC 501_ CRIRK 506_ STYLR 511_ LQLLA 516_ KEEYK 521_ LSLLM 526_ AESLR 531_ GDQVA 536_ PVLYQ 541_ PHLEA 546_ LDRRL 551_ RVVLK 556_ AVRDC 561_ VERNG 566_ LHSVV 571_ DDDLD 576_TEHRA
1: Golgi serine/threonine protein kinase that phosphorylates secretory pathway proteins within Ser-x-Glu/pSer motifs and plays a key role in biomineralization of bones and teeth (PubMed:22582013, PubMed:23754375, PubMed:25789606). Constitutes the main protein kinase for extracellular proteins, generating the majority of the extracellular phosphoproteome (PubMed:26091039). Mainly phosphorylates proteins within the Ser-x-Glu/pSer motif, but also displays a broader substrate specificity (PubMed:26091039). Phosphorylates ERO1A, enhancing its activity which is required to maintain endoplasmic reticulum redox homeostasis and for oxidative protein folding (PubMed:29858230, PubMed:34349020). During endoplasmic reticulum stress, phosphorylates P4HB/PDIA1 which induces a functional switch, causing P4HB to change from an oxidoreductase to a molecular chaperone (PubMed:32149426). This is critical to maintain ER proteostasis and reduce cell death under ER stress (PubMed:32149426). Phosphorylation of P4HB also promotes its interaction with ERN1, leading to reduced activity of ERN1, a key sensor for the endoplasmic reticulum unfolded protein response (PubMed:32149426). Required for osteoblast differentiation and mineralization (PubMed:34349020). Phosphorylates casein as well as a number of proteins involved in biomineralization such as AMELX, AMTN, ENAM and SPP1/OPN (PubMed:22582013, PubMed:25789606, PubMed:34349020). In addition to its role in biomineralization, also plays a role in lipid homeostasis, wound healing and cell migration and adhesion (PubMed:26091039)