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Aliases DOC2B, DOC2BL, double C2 domain beta
External IDs MGI: 1100497 HomoloGene: 20796 GeneCards: DOC2B
Species Human Mouse
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC) Chr 17: 0.14 – 0.18 Mb Chr 11: 75.77 – 75.8 Mb
PubMed search [1] [2]
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Double C2-like domain-containing protein beta is a protein that in humans is encoded by the DOC2B gene.[3][4]


There are at least two protein isoforms of the Double C2 protein, namely alpha (DOC2A) and beta (DOC2B), which contain two C2-like domains. DOC2A and DOC2B are encoded by different genes; these genes are at times confused with the unrelated DAB2 gene which was initially named DOC-2. Doc2b enhances Ca(2+)-dependent exocytosis in adipocytes,[5] chromaffin cells of the adrenal gland[6] and beta cells in the pancreas.[7] In the central nervous system, Doc2b contributes to the spontaneous release of neurotransmitters , which was thought to be acting as a high-affinity Ca(2+) sensor for exocytosis of synaptic vesicles [8] However, further work has shown that while DOC2b is both important for spontaneous exocytosis of synaptic vesicles and binds Calcium, it does not in fact change the calcium dependence of spontaneous synaptic vesicle release and thus can not be the calcium sensor for this process.[9]


  1. ^ "Human PubMed Reference:". 
  2. ^ "Mouse PubMed Reference:". 
  3. ^ Orita S, Sasaki T, Naito A, Komuro R, Ohtsuka T, Maeda M, Suzuki H, Igarashi H, Takai Y (Feb 1995). "Doc2: a novel brain protein having two repeated C2-like domains". Biochem Biophys Res Commun. 206 (2): 439–48. doi:10.1006/bbrc.1995.1062. PMID 7826360. 
  4. ^ "Entrez Gene: DOC2B double C2-like domains, beta". 
  5. ^ Fukuda N, Emoto M, Nakamori Y, Taguchi A, Miyamoto S, Uraki S, Oka Y, Tanizawa Y (Feb 2009). "DOC2B: a novel syntaxin-4 binding protein mediating insulin-regulated GLUT4 vesicle fusion in adipocytes". Diabetes. 58 (2): 377–84. doi:10.2337/db08-0303. PMC 2628611Freely accessible. PMID 19033398. 
  6. ^ Friedrich R, Groffen AJ, Connell E, van Weering JR, Gutman O, Henis YI, Davletov B, Ashery U (Jul 2008). "DOC2B acts as a calcium switch and enhances vesicle fusion". J Neurosci. 28 (27): 6794–806. doi:10.1523/JNEUROSCI.0538-08.2008. PMC 2673511Freely accessible. PMID 18596155. 
  7. ^ Miyazaki M, Emoto M, Fukuda N, Hatanaka M, Taguchi A, Miyamoto S, Tanizawa Y (Jul 2009). "DOC2b is a SNARE regulator of glucose-stimulated delayed insulin secretion". Biochem Biophys Res Commun. 384 (4): 461–5. doi:10.1016/j.bbrc.2009.04.133. PMID 19410553. 
  8. ^ Groffen AJ, Martens S, Díez Arazola R, Cornelisse LN, Lozovaya N, de Jong AP, Goriounova NA, Habets RL, Takai Y, Borst JG, Brose N, McMahon HT, Verhage M (Mar 2010). "Doc2b is a high-affinity Ca2+ sensor for spontaneous neurotransmitter release". Science. 327 (5973): 1614–8. doi:10.1126/science.1183765. PMC 2846320Freely accessible. PMID 20150444. 
  9. ^ *Pang ZP, Bacaj T, Yang X, Zhou P, Xu W, Südhof TC (2011). "Doc2 supports spontaneous synaptic transmission by a Ca2+-independent mechanism". Neuron. 70 (2): 244–251. doi:10.1016/j.neuron.2011.03.011. PMID 21521611. 

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