Follistatin (FS) (Activin-binding protein)
1_MVRAR 6_ HQPGG 11_ LCLLL 16_ LLLCQ 21_ FMEDR 26_ SAQAG 31_ NCWLR 36_ QAKNG 41_ RCQVL 46_ YKTEL 51_ SKEEC 56_ CSTGR 61_ LSTSW 66_ TEEDV 71_ NDNTL 76_ FKWMI 81_ FNGGA 86_ PNCIP 91_ CKETC 96_ ENVDC 101_ GPGKK 106_ CRMNK 111_ KNKPR 116_ CVCAP 121_ DCSNI 126_ TWKGP 131_ VCGLD 136_ GKTYR 141_ NECAL 146_ LKARC 151_ KEQPE 156_ LEVQY 161_ QGRCK 166_ KTCRD 171_ VFCPG 176_ SSTCV 181_ VDQTN 186_ NAYCV 191_ TCNRI 196_ CPEPA 201_ SSEQY 206_ LCGND 211_ GVTYS 216_ SACHL 221_ RKATC 226_ LLGRS 231_ IGLAY 236_ EGKCI 241_ KAKSC 246_ EDIQC 251_ TGGKK 256_ CLWDF 261_ KVGRG 266_ RCSLC 271_ DELCP 276_ DSKSD 281_ EPVCA 286_ SDNAT 291_ YASEC 296_ AMKEA 301_ ACSSG 306_ VLLEV 311_ KHSGS 316_ CNSIS 321_ EDTEE 326_ EEEDE 331_ DQDYS 336_FPISS
1: Multifunctional regulatory protein whose primary function is to antagonize members of the transforming growth factor beta (TGF-beta) superfamily including activin, myostatin, GDF11 or bone morphogenetic proteins (BMPs) (PubMed:11279126, PubMed:16482217, PubMed:18535106). Mechanistically, binds to these ligands in the extracellular space, blocking their type II receptor-binding site to inhibit downstream signaling (PubMed:16482217). Plays an essential role in muscle fiber formation and growth both by preventing the repressive effects of myostatin and through SMAD3/AKT/mTOR signaling independently of myostatin (By similarity). Also promotes neural differentiation by antagonizing the action BMP4 (By similarity). Acts as a specific inhibitor of the biosynthesis and secretion of pituitary follicle stimulating hormone (FSH) by sequestering activin A/INHBA (PubMed:11279126). On the other hand, translocates into the nucleus where it down-regulates rRNA synthesis and ribosome biogenesis to maintain cellular energy homeostasis by binding to rDNA