{PDOC00365}
{PS00422; GRANINS_1}
{PS00423; GRANINS_2}
{BEGIN}
**********************
* Granins signatures *
**********************

Granins (chromogranins or secretogranins) [1] are  a family of acidic proteins
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 known but
they seem to be the precursors of biologically active peptides and/or they may
act  as  helper   proteins  in   the   packaging  of   peptide  hormones   and
neuropeptides. Three members  of this family of  proteins  show some  sequence
similarities:

 - Chromogranin A (CGA) [2]. CGA is a protein of about 420 residues; it is the
   precursor of the  peptide pancreastatin  which  strongly  inhibits glucose-
   induced insulin release from the pancreas.
 - Secretogranin 1 (chromogranin B). A sulfated protein of about 600 residues.
 - Secretogranin 2 (chromogranin C). A sulfated protein of about 650 residues.

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 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.

-Consensus pattern: [DE]-[SN]-L-[SAN]-{EGI}-{ELT}-[DE]-x-E-L
-Sequences known to belong to this class detected by the pattern: ALL,  except
 for mouse and frog secretogranin 2.
-Other sequence(s) detected in Swiss-Prot: 9.

-Consensus pattern: C-[LIVM](2)-E-[LIVM](2)-S-[DN]-[STA]-L-x-K-x-[SN]-x(3)-
                    [LIVM]-[STA]-x-E-C
                    [The 2 C's are linked by a disulfide bond]
-Sequences known to belong to this class detected by the pattern: Chromogranin
 A and B.
-Other sequence(s) detected in Swiss-Prot: NONE.

-Last update: December 2004 / Patterns and text revised.

[ 1] Huttner W.B., Gerdes H.-H., Rosa P.
     "The granin (chromogranin/secretogranin) family."
     Trends Biochem. Sci. 16:27-30(1991).
     PubMed=2053134
[ 2] Simon J.-P., Aunis D.
     "Biochemistry of the chromogranin A protein family."
     Biochem. J. 262:1-13(1989).
     PubMed=2684154

--------------------------------------------------------------------------------
PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and
distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives
(CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html
--------------------------------------------------------------------------------

{END}