General Information

  • ID:  hor003975
  • Uniprot ID:  Q9QXV0
  • Protein name:  KEP
  • Gene name:  Pcsk1n
  • Organism:  Mus musculus (Mouse)
  • Family:  ProSAAS family
  • Source:  animal
  • Expression:  Broadly expressed from 9 dpc to 11 dpc, with some enrichment in neural tube-derived tissues. By 15 dpc, the expression is largely restricted to neuroendocrine tissues. |Expressed in brain (mostly hypothalamus and pituitary) and gut. Expressed in trigemina
  • Disease:  NA
  • Comments:  NA
  • Taxonomy:  Mus (subgenus), Mus (genus), Murinae (subfamily), Muridae (family), Muroidea, Myomorpha (suborder), Rodentia (order), Glires, Euarchontoglires (superorder), Boreoeutheria, Eutheria, Theria, Mammalia (class), Amniota, Tetrapoda, Dipnotetrapodomorpha, Sarcopterygii (superclass), Euteleostomi, Teleostomi, Gnathostomata, Vertebrata, Craniata (subphylum), Chordata (phylum), Deuterostomia, Bilateria, Eumetazoa, Metazoa (kingdom), Opisthokonta, Eukaryota (superkingdom), cellular organisms
  • GO MF:  GO:0004866 endopeptidase inhibitor activity; GO:0004867 serine-type endopeptidase inhibitor activity
  • GO BP:  GO:0002021 response to dietary excess; GO:0007218 neuropeptide signaling pathway; GO:0009409 response to cold; GO:0016486 peptide hormone processing
  • GO CC:  GO:0005576 extracellular region; GO:0005615 extracellular space; GO:0005794 Golgi apparatus; GO:0005802 trans-Golgi network; GO:0030141 secretory granule

Sequence Information

  • Sequence:  ARPVKEP
  • Length:  7
  • Propeptide:  MAGSPLLCGPRAGGVGILVLLLLGLLRLPPTLSARPVKEPRSLSAASAPLVETSTPLRLRRAVPRGEAAGAVQELARALAHLLEAERQERARAEAQEAEDQQARVLAQLLRAWGSPRASDPPLAPDDDPDAPAAQLARALLRARLDPAALAAQLVPAPAAAPRPRPPVYDDGPTGPDVEDAGDETPDVDPELLRYLLGRILTGSSEPEAAPAPRRLRRSVDQDLGPEVPPENVLGALLRVKRLENPSPQAPARRLLPP
  • Signal peptide:  MAGSPLLCGPRAGGVGILVLLLLGLLRLPPTLS
  • Modification:  NA
  • Glycosylation:  NA
  • Mutagenesis:  NA

Activity

  • Function:  May function in the control of the neuroendocrine secretory pathway. Proposed be a specific endogenous inhibitor of PCSK1. ProSAAS and Big PEN-LEN, both containing the C-terminal inhibitory domain, but not the processed peptides reduce PCSK1 activity in the endoplasmic reticulum and Golgi. It reduces the activity of the 87 kDa form but not the autocatalytically derived 66 kDa form of PCSK1. Subsequent processing of proSAAS may eliminate the inhibition. Slows down convertase-mediated processing of proopiomelanocortin and proenkephalin. May control the intracellular timing of PCSK1 rather than its total level of activity.
  • Mechanism:  NA
  • Cross BBB:  NA
  • Target:  Pcsk1
  • Target Unid:  Q9QXV0
  • IC50: NA
  • EC50: NA
  • ED50: NA
  • kd: NA
  • Half life: NA

Structure

  • Disulfide bond:  NA
  • Structure ID:  AF-Q9QXV0-F1(AlphaFold_DB_ID)

  • Structure: (PDB_ID-from https://www.rcsb.org/; AlphaFold_DB_ID-from https://alphafold.ebi.ac.uk/; hordbxxxxxx_AF2.pdb was predicted structure by AlphaFold2; hordbxxxxxx_ESM.pdb was predicted structure by ESMFold)
    •    hor003975_AF2.pdbhor003975_ESM.pdb

Physical Information

Mass: 90313 Formula: C35H61N11O10
Absent amino acids: CDFGHILMNQSTWY Common amino acids: P
pI: 9.69 Basic residues: 2
Polar residues: 0 Hydrophobic residues: 2
Hydrophobicity: -130 Boman Index: -2143
Half-Life: 4.4 hour Half-Life Yeast: >20 hour
Half-Life E.Coli: >10 hour Aliphatic Index 55.71
Instability Index: 8700 Extinction Coefficient cystines: 0
Absorbance 280nm: 0

Literature

  • PubMed ID:  11094058
  • Title:  ProSAAS Processing in Mouse Brain and Pituitary