Corticotropin-releasing hormones
| Corticotropin-releasing hormones | ||
|---|---|---|
|
Existing structural data: 1go9, 1goe |
||
| Properties of human protein | ||
| Mass / length primary structure | 41 aa; 4.76 kDa | |
| Precursor | (191 aa) | |
| Identifier | ||
| Gene names | CRH ; CRF | |
| External IDs | ||
| Occurrence | ||
| Parent taxon | Euteleostomi | |
| Orthologue | ||
| human | mouse | |
| Entrez | 1392 | 12918 |
| Ensemble | ENSG00000147571 | ENSMUSG00000049796 |
| UniProt | P06850 | Q14AA2 |
| Refseq (mRNA) | NM_000756 | NM_205769 |
| Refseq (protein) | NP_000747 | NP_991338 |
| Gene locus | Chr 8: 67.25 - 67.25 Mb | Chr 3: 19.89 - 19.89 Mb |
| PubMed search | 1392 |
12918
|
The corticotropin-releasing hormone ( CRH ) or the corticotropin-releasing factor ( CRF ), also called corticoliberin , is a polypeptide that consists of 41 amino acids and is formed in the paraventricular nucleus of the hypothalamus . From there it reaches the anterior pituitary lobe via portal vessels , where it activates the cAMP -dependent protein kinase A. This in turn stimulates v. a. the release of ACTH (adrenocorticotropic hormone) and activates the sympathetic system .
The release of CRH is subject to a circadian rhythm (stronger secretion in the morning than in the evening), impulses from the limbic system and the negative feedback from the glucocorticoids formed under the influence of ACTH .
The secretion is also stimulated by IL-1β and TNF ; the endogenous cortisone release is thus adapted to an inflammatory process in the body.
effect
In addition to the basal and stress-induced secretion of adrenocorticotropic hormone ( ACTH ) and other proopiomelanocortin (POMC) related peptides , endocrine function and control of the hypothalamic-pituitary-adrenal axis, CRF also appears to be involved in many other central and peripheral processes to be. Participation in the cardiovascular system, inflammation, the reproductive system, pregnancy, thermoregulation , food intake and the psyche is suspected.
education
CRH is mainly formed in the small cell portion of the paraventricular nucleus of the hypothalamus. However, synthesis of CRH also takes place in other CNS regions such as in the brain stem and other peripheral organs (e.g. lungs, adrenal glands, gastrointestinal tract).
exploration
The CRH was first isolated and characterized from sheep hypothalami in 1981 . The CRF peptide is not identical in all species. Different CRF peptides exist in different species, the sequence of which differs more or less from human CRF.
After the 41 amino acid oCRF (ovine) by Vale et al. was isolated from sheep hypothalami, the sequencing of identical rCRF (rat) and hCRF (human) followed as early as 1983. oCRF differs from r / hCRF in seven of the 41 amino acids. Subsequently, two non-mammalian CRF peptides, Sauvagin and Urotensin-I, were discovered. Sauvagin consists of 40 amino acids and was isolated from the skin of the frog ( Phyllomedusa sauvagei ). Urotensin-I contains 41 amino acids and was found in the nervous system of the sucker fish ( Catostomus commersoni ) (Grigoriadis et al., 2001). Both non-mammalian CRF peptides show an astonishingly high sequence homology (approx. 50%) with hCRF.
In 1995, a CRF-related peptide, urocortin , was found in mammalian organisms by Joan Vaughan and co-workers .
Individual evidence
- ↑ Rivest S et al .: How the Blood Talks to the Brain Parenchyma and the Paraventricular Nucleus of the Hypothalamus During Systemic Inflammatory and Infectious Stimuli. Proc Soc Exp Biol Med 2000; 223 (1): 22-38
- ^ Hans-Christian Pape, Armin Kurtz, Stefan Silbernagl: Physiology . 7th edition. Georg Thieme Verlag, Stuttgart 2014, ISBN 978-3-13-796007-2 , p. 608 .