Granin

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This article is about the protein family. For other uses of Granin, see Granin (disambiguation).
Granin (chromogranin or secretogranin)
PDB 1n2y EBI.jpg
Structure of SS-cyclized catestatin fragment from chromogranin A.[1]
Identifiers
Symbol Granin
Pfam PF01271
InterPro IPR001990
PROSITE PDOC00365
SCOP 1cfk
SUPERFAMILY 1cfk
OPM superfamily 328
OPM protein 1lv4

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[edit]

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[edit]

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]

Members[edit]

Chromogranins[edit]

chromogranin A
(parathyroid secretory protein 1)
Identifiers
Symbol CHGA
Alt. symbols CGA
Entrez 1113
HUGO 1929
OMIM 118910
RefSeq NM_001275
UniProt P10645
Other data
Locus Chr. 14 q32
chromogranin B
(secretogranin 1)
Identifiers
Symbol CHGB
Alt. symbols SCG1
Entrez 1114
HUGO 1930
OMIM 118920
RefSeq NM_001819
UniProt P05060
Other data
Locus Chr. 20 pter-p12

Secretogranins[edit]

secretogranin II
(chromogranin C)
Identifiers
Symbol SCG2
Alt. symbols CHGC, SgII
Entrez 7857
HUGO 10575
OMIM 118930
RefSeq NM_003469
UniProt P13521
Other data
Locus Chr. 2 q35-q36
secretogranin III
(FLJ90833)
Identifiers
Symbol SCG3
Alt. symbols SGIII
Entrez 29106
HUGO 13707
OMIM 611796
RefSeq NM_013243
UniProt Q8WXD2
Other data
Locus Chr. 15 q21.3
secretogranin V
(7B2 protein)
Identifiers
Symbol SCG5
Alt. symbols SGNE1
Entrez 6447
HUGO 10816
OMIM 173120
RefSeq NM_003020
UniProt P05408
Other data
Locus Chr. 15 q13-q14

Two other proteins (secretogranin IV and VI) are also proposed to belong to the granins on the basis of their physico-chemical properties.

References[edit]

  1. ^ Preece NE, Nguyen M, Mahata M, et al. (April 2004). "Conformational preferences and activities of peptides from the catecholamine release-inhibitory (catestatin) region of chromogranin A". Regul. Pept. 118 (1-2): 75–87. doi:10.1016/j.regpep.2003.10.035. PMID 14759560. 
  2. ^ Huttner WB, Gerdes HH, Rosa P (January 1991). "The granin (chromogranin/secretogranin) family". Trends Biochem. Sci. 16 (1): 27–30. doi:10.1016/0968-0004(91)90012-K. PMID 2053134. 
  3. ^ Stridsberg, M (1 June 2000). "Characterisation of N-terminal chromogranin A and chromogranin B in mammals by region-specific radioimmunoassays and chromatographic separation methods". Journal of Endocrinology 165 (3): 703–714. doi:10.1677/joe.0.1650703. 
  4. ^ Stridsberg, Mats; Pettersson, Ann; Hagman, Ragnvi; Westin, Christoffer; Höglund, Odd (2014). "Chromogranins can be measured in samples from cats and dogs". BMC Research Notes 7 (1): 336. doi:10.1186/1756-0500-7-336. 
  5. ^ Hoglund, O. V.; Hagman, R.; Stridsberg, M. (27 March 2015). "Chromogranin A and cortisol at intraoperative repeated noxious stimuli: Surgical stress in a dog model" (PDF). SAGE Open Medicine 3 (0). doi:10.1177/2050312115576432. 

External links[edit]

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