SCG5 explained

Neuroendocrine protein 7B2 is a protein that in humans is encoded by the SCG5 gene.^{[1] [2] [3]} The protein expressed by this gene is widely distributed in neuroendocrine tissues. It functions as a chaperone protein for the proprotein convertase PC2 by blocking the aggregation of this protein, and is required for the production of an active PC2 enzyme.^{[4] [5]} It is an intrinsically disordered protein that may also function as a chaperone for other aggregating secretory proteins in addition to proPC2 (Helwig et al. 2013). 7B2 has been identified in vertebrates and in invertebrates as low as flatworms (Protein ID: AIZ72728.1) and insects.^[6] It is also called Sgne1 and Secretogranin V. In C. elegans, it was originally called e7B2^[7] and then renamed Seven B Two (gene name sbt-1).^[8] There is a Pfam entry for this protein: Secretogranin_V (PF05281).

Further reading

• Mbikay M, Seidah NG, Chrétien M . Neuroendocrine secretory protein 7B2: structure, expression and functions . The Biochemical Journal . 357 . Pt 2 . 329–42 . July 2001 . 11439082 . 1221959 . 10.1042/0264-6021:3570329 .
• Paquet L, Lazure C, Seidah NG, Chrétien M, Mbikay M . The production by alternate splicing of two mRNAs differing by one codon could be an intrinsic property of neuroendocrine protein 7B2 gene expression in man . Biochemical and Biophysical Research Communications . 174 . 1 . 156–62 . January 1991 . 1989596 . 10.1016/0006-291X(91)90499-W .
• Roebroek AJ, Dehaen MR, van Bokhoven A, Martens GJ, Marÿnen P, van den Berghe H, Van de Ven WJ . Regional mapping of the human gene encoding the novel pituitary polypeptide 7B2 to chromosome 15q13----q14 by in situ hybridization . Cytogenetics and Cell Genetics . 50 . 2–3 . 158–60 . 1989 . 2776483 . 10.1159/000132749 .
• Benjannet S, Marcinkiewicz M, Falgueyret JP, Johnson DE, Seidah NG, Chrétien M . Secretory protein 7B2 is associated with pancreatic hormones within normal islets and some experimentally induced tumors . Endocrinology . 123 . 2 . 874–84 . August 1988 . 2840270 . 10.1210/endo-123-2-874 .
• Martens GJ . Cloning and sequence analysis of human pituitary cDNA encoding the novel polypeptide 7B2 . FEBS Letters . 234 . 1 . 160–4 . July 1988 . 3134253 . 10.1016/0014-5793(88)81324-3 . free .
• Brayton KA, Aimi J, Qiu H, Yazdanparast R, Ghatei MA, Polak JM, Bloom SR, Dixon JE . 6 . Cloning, characterization, and sequence of a porcine cDNA encoding a secreted neuronal and endocrine protein . DNA . 7 . 10 . 713–9 . December 1988 . 3234177 . 10.1089/dna.1988.7.713 .
• Marcinkiewicz M, Benjannet S, Falgueyret JP, Seidah NG, Schürch W, Verdy M, Cantin M, Chrétien M . 6 . Identification and localization of 7B2 protein in human, porcine, and rat thyroid gland and in human medullary carcinoma . Endocrinology . 123 . 2 . 866–73 . August 1988 . 3293987 . 10.1210/endo-123-2-866 .
• Marcinkiewicz M, Benjannet S, Cantin M, Seidah NG, Chrétien M . CNS distribution of a novel pituitary protein '7B2': localization in secretory and synaptic vesicles . Brain Research . 380 . 2 . 349–56 . August 1986 . 3530373 . 10.1016/0006-8993(86)90233-7 . 22326257 .
• Seidah NG, Hsi KL, De Serres G, Rochemont J, Hamelin J, Antakly T, Cantin M, Chrétien M . 6 . Isolation and NH2-terminal sequence of a highly conserved human and porcine pituitary protein belonging to a new superfamily. Immunocytochemical localization in pars distalis and pars nervosa of the pituitary and in the supraoptic nucleus of the hypothalamus . Archives of Biochemistry and Biophysics . 225 . 2 . 525–34 . September 1983 . 6625600 . 10.1016/0003-9861(83)90063-2 .
• Benjannet S, Savaria D, Chrétien M, Seidah NG . 7B2 is a specific intracellular binding protein of the prohormone convertase PC2 . Journal of Neurochemistry . 64 . 5 . 2303–11 . May 1995 . 7722516 . 10.1046/j.1471-4159.1995.64052303.x . 7133644 .
• Braks JA, Martens GJ . 7B2 is a neuroendocrine chaperone that transiently interacts with prohormone convertase PC2 in the secretory pathway . Cell . 78 . 2 . 263–73 . July 1994 . 7913882 . 10.1016/0092-8674(94)90296-8 . 24734254 .
• Braks JA, Broers CA, Danger JM, Martens GJ . Structural organization of the gene encoding the neuroendocrine chaperone 7B2 . European Journal of Biochemistry . 236 . 1 . 60–7 . February 1996 . 8617287 . 10.1111/j.1432-1033.1996.00060.x . free .
• Bourdeau I, Antonini SR, Lacroix A, Kirschner LS, Matyakhina L, Lorang D, Libutti SK, Stratakis CA . 6 . Gene array analysis of macronodular adrenal hyperplasia confirms clinical heterogeneity and identifies several candidate genes as molecular mediators . Oncogene . 23 . 8 . 1575–85 . February 2004 . 14767469 . 10.1038/sj.onc.1207277 . 25336472 .
• Lim J, Hao T, Shaw C, Patel AJ, Szabó G, Rual JF, Fisk CJ, Li N, Smolyar A, Hill DE, Barabási AL, Vidal M, Zoghbi HY . 6 . A protein-protein interaction network for human inherited ataxias and disorders of Purkinje cell degeneration . Cell . 125 . 4 . 801–14 . May 2006 . 16713569 . 10.1016/j.cell.2006.03.032 . free .
• Dasgupta I, Sanglas L, Enghild JJ, Lindberg I . The neuroendocrine protein 7B2 is intrinsically disordered . Biochemistry . 51 . 38 . 7456–64 . September 2012 . 22947085 . 3457758 . 10.1021/bi300871k .
• Helwig M, Hoshino A, Berridge C, Lee SN, Lorenzen N, Otzen DE, Eriksen JL, Lindberg I . 6 . The neuroendocrine protein 7B2 suppresses the aggregation of neurodegenerative disease-related proteins . The Journal of Biological Chemistry . 288 . 2 . 1114–24 . January 2013 . 23172224 . 3542996 . 10.1074/jbc.M112.417071 . free .

Notes and References

1. Lloyd RV, Jin L . Analysis of chromogranin/secretogranin messenger RNAs in human pituitary adenomas . Diagnostic Molecular Pathology . 3 . 1 . 38–45 . March 1994 . 8162254 . 10.1097/00019606-199403010-00007 .
2. Taupenot L, Harper KL, O'Connor DT . The chromogranin-secretogranin family . The New England Journal of Medicine . 348 . 12 . 1134–49 . March 2003 . 12646671 . 10.1056/NEJMra021405 .
3. Martens GJ . Cloning and sequence analysis of human pituitary cDNA encoding the novel polypeptide 7B2 . FEBS Letters . 234 . 1 . 160–4 . July 1988 . 3134253 . 10.1016/0014-5793(88)81324-3 . free .
4. Web site: Entrez Gene: SCG5 secretogranin V (7B2 protein).
5. Mbikay M, Seidah NG, Chrétien M . Neuroendocrine secretory protein 7B2: structure, expression and functions . The Biochemical Journal . 357 . Pt 2 . 329–42 . July 2001 . 11439082 . 1221959 . 10.1042/0264-6021:3570329 .
6. Hwang JR, Siekhaus DE, Fuller RS, Taghert PH, Lindberg I . Interaction of Drosophila melanogaster prohormone convertase 2 and 7B2. Insect cell-specific processing and secretion . The Journal of Biological Chemistry . 275 . 23 . 17886–93 . June 2000 . 10749852 . 10.1074/jbc.M000032200 . free .
7. Lindberg I, Tu B, Muller L, Dicksinson I . Cloning and functional analysis of C. elegans 7B2 . DNA and Cell Biology . 17 . 8 . 727–734 . August 1998 . 9726255 . 10.1089/dna.1998.17.727.
8. Sieburth et al. Systematic analysis of genes required for synapse structure and function . Nature . 436 . 7050 . 510–517 . July 2005 . 16049479 . 10.1038/nature03809. 2005Natur.436..510S . 4427397 .