P84351
uniprot
P84351
canonical
amino_acid_sequence
REVCELNPDCDELADHIGFQEAYR
uniprot
proteins
function
FUNCTION: The carboxylated form is one of the main organic components of the bone matrix, which constitutes 1-2% of the total bone protein (By similarity). Acts as a negative regulator of bone formation and is required to limit bone formation without impairing bone resorption or mineralization (By similarity). Binds strongly to apatite and calcium upon gamma-carboxylation; this modification is essential for bone metabolism (By similarity). {ECO:0000250|UniProtKB:P86546}.; FUNCTION: The uncarboxylated form acts as a hormone secreted by osteoblasts, which regulates different cellular processes, such as energy metabolism, male fertility and brain development. Regulates of energy metabolism by acting as a hormone favoring pancreatic beta-cell proliferation, insulin secretion and sensitivity and energy expenditure. Uncarboxylated osteocalcin hormone also promotes testosterone production in the testes: acts as a ligand for G protein-coupled receptor GPRC6A at the surface of Leydig cells, initiating a signaling response that promotes the expression of enzymes required for testosterone synthesis in a CREB-dependent manner. Also acts as a regulator of brain development: osteocalcin hormone crosses the blood-brain barrier and acts as a ligand for GPR158 on neurons, initiating a signaling response that prevents neuronal apoptosis in the hippocampus, favors the synthesis of all monoamine neurotransmitters and inhibits that of gamma-aminobutyric acid (GABA). Osteocalcin also crosses the placenta during pregnancy and maternal osteocalcin is required for fetal brain development. {ECO:0000250|UniProtKB:P86546}.
uniprot
proteins
mass_dalton
2823
uniprot
proteins
post_translational_modification
PTM: Carboxylated by vitamin K-dependent GGCX to form gamma-carboxyglutamate; these residues are essential for the binding of calcium (By similarity). Decarboxylation promotes the hormone activity (By similarity). {ECO:0000250|UniProtKB:P02818, ECO:0000250|UniProtKB:P86546, ECO:0000255|PROSITE-ProRule:PRU00463}.
uniprot
proteins
protein_family
Osteocalcin/matrix Gla protein family
uniprot
proteins
pubmed
15753298
uniprot
proteins
sequence_length
24
uniprot
proteins
subcellular_location
SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:15753298}.
uniprot
proteins