Biology:Granin

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Granin (chromogranin or secretogranin)
PDB 1n2y EBI.jpg
Structure of SS-cyclized catestatin fragment from chromogranin A.[1]
Identifiers
SymbolGranin
PfamPF01271
InterProIPR001990
PROSITEPDOC00365
SCOP21cfk / SCOPe / SUPFAM
OPM superfamily282
OPM protein1lv4

Granin (chromogranin and secretogranin) is a protein family of regulated secretory proteins ubiquitously found in the cores of amine and peptide hormone and neurotransmitter dense-core secretory vesicles.[2]

Function

Granins (chromogranins or secretogranins) are acidic proteins and are present in the secretory granules of a wide variety of endocrine and neuro-endocrine cells. The exact function(s) of these proteins is not yet settled but there is evidence that granins function as pro-hormones, giving rise to an array of peptide fragments for which autocrine, paracrine, and endocrine activities have been demonstrated in vitro and in vivo. The intracellular biochemistry of granins includes binding of Ca2+, ATP and catecholamines (epinephrine, norepinephrine) within the hormone storage vesicle core. There is also evidence that CgA, and perhaps other granins, regulate the biogenesis of dense-core secretory vesicles and hormone sequestration in neuroendocrine cells.

Structure

Apart from their subcellular location and the abundance of acidic residues (Asp and Glu), these proteins do not share many structural similarities. Only one short region, located in the C-terminal section, is conserved in all these proteins. Chromogranins and secretogranins together share a C-terminal motif, whereas chromogranins A and B share a region of high similarity in their N-terminal section; this region includes two cysteine residues involved in a disulfide bond.

There are considerable differences in the amino acid composition between different animals. Commercial assays for measuring human CGA can usually not be used for measuring CGA in samples from other species. Some specific parts of the molecule have a higher degree of amino acid homology and methods where the antibodies are directed against specific epitopes can be used to measure samples from different animals.[3] Region-specific assays measuring defined parts of CGA, CGB and SG2 can be used for measurements in samples from cats and dogs.[4][5][6][7]

Members

Chromogranins

chromogranin A
(parathyroid secretory protein 1)
Identifiers
SymbolCHGA
Alt. symbolsCGA
NCBI gene1113
HGNC1929
OMIM118910
RefSeqNM_001275
UniProtP10645
Other data
LocusChr. 14 q32
chromogranin B
(secretogranin 1)
Identifiers
SymbolCHGB
Alt. symbolsSCG1
NCBI gene1114
HGNC1930
OMIM118920
RefSeqNM_001819
UniProtP05060
Other data
LocusChr. 20 pter-p12

Secretogranins

secretogranin II
(chromogranin C)
Identifiers
SymbolSCG2
Alt. symbolsCHGC, SgII
NCBI gene7857
HGNC10575
OMIM118930
RefSeqNM_003469
UniProtP13521
Other data
LocusChr. 2 q35-q36
secretogranin III
(FLJ90833)
Identifiers
SymbolSCG3
Alt. symbolsSGIII
NCBI gene29106
HGNC13707
OMIM611796
RefSeqNM_013243
UniProtQ8WXD2
Other data
LocusChr. 15 q21.3
secretogranin V
(7B2 protein)
Identifiers
SymbolSCG5
Alt. symbolsSGNE1
NCBI gene6447
HGNC10816
OMIM173120
RefSeqNM_003020
UniProtP05408
Other data
LocusChr. 15 q13-q14

Extended group

Some other proteins are also proposed to belong to the granins based on their physico-chemical properties. These include NESP55 (SgVI), VGF (SgVII), and ProSAAS (SgVIII).[8]

References

  1. "Conformational preferences and activities of peptides from the catecholamine release-inhibitory (catestatin) region of chromogranin A". Regulatory Peptides 118 (1–2): 75–87. April 2004. doi:10.1016/j.regpep.2003.10.035. PMID 14759560. 
  2. "The granin (chromogranin/secretogranin) family". Trends in Biochemical Sciences 16 (1): 27–30. January 1991. doi:10.1016/0968-0004(91)90012-K. PMID 2053134. 
  3. "Characterisation of N-terminal chromogranin A and chromogranin B in mammals by region-specific radioimmunoassays and chromatographic separation methods". The Journal of Endocrinology 165 (3): 703–14. June 2000. doi:10.1677/joe.0.1650703. PMID 10828855. 
  4. "Chromogranins can be measured in samples from cats and dogs". BMC Research Notes 7 (1): 336. June 2014. doi:10.1186/1756-0500-7-336. PMID 24899097. 
  5. "Chromogranin A and cortisol at intraoperative repeated noxious stimuli: Surgical stress in a dog model". SAGE Open Medicine 3: 2050312115576432. 27 March 2015. doi:10.1177/2050312115576432. PMID 26770773. 
  6. "Catestatin, vasostatin, cortisol, temperature, heart rate, respiratory rate, scores of the short form of the Glasgow composite measure pain scale and visual analog scale for stress and pain behavior in dogs before and after ovariohysterectomy". BMC Research Notes 9 (1): 381. August 2016. doi:10.1186/s13104-016-2193-1. PMID 27484122. 
  7. "Catestatin and vasostatin concentrations in healthy dogs". Acta Veterinaria Scandinavica 59 (1): 1. January 2017. doi:10.1186/s13028-016-0274-8. PMID 28049540. 
  8. "The extended granin family: structure, function, and biomedical implications". Endocrine Reviews 32 (6): 755–97. December 2011. doi:10.1210/er.2010-0027. PMID 21862681. 

External links

This article incorporates text from the public domain Pfam and InterPro: IPR001990