This gene encodes ghrelin-obestatin preproprotein, which generates ghrelin and obestatin. Ghrelin is an endogenous ligand for the growth hormone secretagogue receptor and is involved in regulating growth hormone release. Obestatin was initially reported to be an endogenous ligand for the orphan G protein-coupled receptor GPR39 and was involved in satiety and decreased food intake; however, these findings are controversial. Recent reports show that obestatin is involved in inhibiting thirst and anxiety, improving memory, regulating sleep, affecting cell proliferation, and increasing the secretion of pancreatic juice enzymes. Alternative promoters and alternative splicing result in multiple transcript variants, some of which encode different protein isoforms and some of which do not encode a protein but may regulate the ghrelin-obestatin preproprotein expression. In addition, antisense transcripts for this gene have been identified and may also function in regulation of the ghrelin-obestatin preproprotein expression. [provided by RefSeq, Oct 2008].
Function:
Ghrelin is the ligand for growth hormone secretagogue receptor type 1 (GHSR). Induces the release of growth hormone from the pituitary. Has an appetite-stimulating effect, induces adiposity and stimulates gastric acid secretion. Involved in growth regulation.
Obestatin may be the ligand for GPR39. May have an appetite-reducing effect resulting in decreased food intake. May reduce gastric emptying activity and jejunal motility.
Subcellular Location:
Secreted.
Tissue Specificity:
Highest level in stomach. All forms are found in serum as well. Other tissues compensate for the loss of ghrelin synthesis in the stomach following gastrectomy.
Post-translational modifications:
O-octanoylation or O-decanoylation is essential for ghrelin activity. The O-decanoylated forms Ghrelin-27-C10 and Ghrelin-28-C10 differ in the length of the carbon backbone of the carboxylic acid bound to Ser-26. A small fraction of ghrelin, ghrelin-28-C10:1, may be modified with a singly unsaturated carboxylic acid.
Amidation of Leu-98 is essential for obestatin activity.
Similarity:
Belongs to the motilin family.
SWISS:
Q9UBU3
Gene ID:
51738
Database links:
Entrez Gene: 51738 Human
Entrez Gene: 58991 Mouse
Entrez Gene: 59301 Rat
Entrez Gene: 574280 Rhesus monkey
Omim: 605353 Human
SwissProt: Q6BEG6 Cat
SwissProt: Q9BEF8 Dog
SwissProt: Q9UBU3 Human
SwissProt: Q9EQX0 Mouse
SwissProt: Q9GKY5 Pig
SwissProt: Q9QYH7 Rat
Unigene: 590080 Human
Unigene: 672979 Human
Unigene: 379095 Mouse
Unigene: 42103 Rat
| Picture |
Paraformaldehyde-fixed, paraffin embedded (rat intestine tissue); Antigen retrieval by boiling in sodium citrate buffer (pH6.0) for 15min; Block endogenous peroxidase by 3% hydrogen peroxide for 20 minutes; Blocking buffer (normal goat serum) at 37°C for 30min; Antibody incubation with (Ghrelin 28 (n-octanoyl Ser26)) Polyclonal Antibody, Unconjugated (SL10413R) at 1:400 overnight at 4°C, followed by a conjugated secondary (sp-0023) for 20 minutes and DAB staining.
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