Gene Symbol: Sytl4
Description: synaptotagmin-like 4
Alias: Gph, Slp4, synaptotagmin-like protein 4, exophilin-2, granuphilin-a, granuphilin-b
Species: mouse
Products:     Sytl4

Top Publications

  1. Wang J, Takeuchi T, Yokota H, Izumi T. Novel rabphilin-3-like protein associates with insulin-containing granules in pancreatic beta cells. J Biol Chem. 1999;274:28542-8 pubmed
    ..These distinctive characteristics of granuphilin suggest that it is not a simple counterpart of rabphilin-3 in endocrine cells and that it has a unique role in the regulated exocytosis of dense-core granules in endocrine tissues. ..
  2. Torii S, Takeuchi T, Nagamatsu S, Izumi T. Rab27 effector granuphilin promotes the plasma membrane targeting of insulin granules via interaction with syntaxin 1a. J Biol Chem. 2004;279:22532-8 pubmed
    ..The complex formation of these three proteins may contribute to the specificity of the targeting process during the exocytosis of insulin granules. ..
  3. Gomi H, Mizutani S, Kasai K, Itohara S, Izumi T. Granuphilin molecularly docks insulin granules to the fusion machinery. J Cell Biol. 2005;171:99-109 pubmed
    ..These findings provide a novel paradigm for the docking machinery in regulated exocytosis. ..
  4. Gomi H, Mori K, Itohara S, Izumi T. Rab27b is expressed in a wide range of exocytic cells and involved in the delivery of secretory granules near the plasma membrane. Mol Biol Cell. 2007;18:4377-86 pubmed
    ..In conjunction with a phenotype having a pituitary devoid of the Rab27 effector granuphilin, we discuss the relationship between the residence and the releasable pool of granules. ..
  5. Fukuda M, Mikoshiba K. Synaptotagmin-like protein 1-3: a novel family of C-terminal-type tandem C2 proteins. Biochem Biophys Res Commun. 2001;281:1226-33 pubmed
    ..In addition, Slp family proteins are differentially distributed in different mouse tissues and at different developmental stages. ..
  6. Fukuda M, Saegusa C, Mikoshiba K. Novel splicing isoforms of synaptotagmin-like proteins 2 and 3: identification of the Slp homology domain. Biochem Biophys Res Commun. 2001;283:513-9 pubmed
    ..Sequence alignment of the Slp1, Slp2-a, Slp3-a, and Slp4 amino terminal domains reveals the presence of two conserved regions among the Slp family, designated SHD1 (Slp ..
  7. Torii S, Zhao S, Yi Z, Takeuchi T, Izumi T. Granuphilin modulates the exocytosis of secretory granules through interaction with syntaxin 1a. Mol Cell Biol. 2002;22:5518-26 pubmed
    ..Thus, granuphilin is the first regulator in the exocytotic pathway that functions by directly connecting two critical vesicle transport proteins, Rab and SNARE. ..
  8. Wang H, Ishizaki R, Kobayashi E, Fujiwara T, Akagawa K, Izumi T. Loss of granuphilin and loss of syntaxin-1A cause differential effects on insulin granule docking and fusion. J Biol Chem. 2011;286:32244-50 pubmed publisher
    The Rab27 effector granuphilin/Slp4 is essential for the stable attachment (docking) of secretory granules to the plasma membrane, and it also inhibits subsequent fusion...
  9. Zhao S, Torii S, Yokota Hashimoto H, Takeuchi T, Izumi T. Involvement of Rab27b in the regulated secretion of pituitary hormones. Endocrinology. 2002;143:1817-24 pubmed

More Information


  1. Kato T, Shimano H, Yamamoto T, Yokoo T, Endo Y, Ishikawa M, et al. Granuphilin is activated by SREBP-1c and involved in impaired insulin secretion in diabetic mice. Cell Metab. 2006;4:143-54 pubmed
    ..Collectively, our data provide evidence that activation of the SREBP-1c/granuphilin pathway is a potential mechanism for impaired insulin secretion in diabetes, contributing to beta cell lipotoxicity. ..
  2. Chavas L, Ihara K, Kawasaki M, Torii S, Uejima T, Kato R, et al. Elucidation of Rab27 recruitment by its effectors: structure of Rab27a bound to Exophilin4/Slp2-a. Structure. 2008;16:1468-77 pubmed publisher
    ..The observed structural complementation between the interacting surfaces of Rab27a and Exophilin4 sheds light on the disparities among the Rab27 effectors and outlines a general mechanism for their recruitment. ..
  3. Xu X, Coats J, Yang C, Wang A, Ahmed O, Alvarado M, et al. Modular genetic control of sexually dimorphic behaviors. Cell. 2012;148:596-607 pubmed publisher
    ..Indeed, we find that mice with targeted disruptions of each of four of these genes (Brs3, Cckar, Irs4, Sytl4) exhibit extremely specific deficits in sex specific behaviors, with single genes controlling the pattern or ..
  4. Wang H, Ishizaki R, Xu J, Kasai K, Kobayashi E, Gomi H, et al. The Rab27a effector exophilin7 promotes fusion of secretory granules that have not been docked to the plasma membrane. Mol Biol Cell. 2013;24:319-30 pubmed publisher
    ..These findings indicate that the two Rab27a effectors, granuphilin and exophilin7, differentially regulate the exocytosis of either stably or minimally docked granules, respectively. ..
  5. Neophytou P, Muir E, Hutton J. A subtractive cloning approach to the identification of mRNAs specifically expressed in pancreatic beta-cells. Diabetes. 1996;45:127-33 pubmed
    ..When combined with functional or immunological screening procedures, the approach will be useful for the isolation of beta-cell-specific molecules for immunological and genetic investigations of beta-cell function and pathology. ..
  6. Strom M, Hume A, Tarafder A, Barkagianni E, Seabra M. A family of Rab27-binding proteins. Melanophilin links Rab27a and myosin Va function in melanosome transport. J Biol Chem. 2002;277:25423-30 pubmed
    ..Thus, melanophilin can associate simultaneously with activated Rab27a and myosin Va via distinct regions, and serve as a linker between these proteins. ..
  7. Holt O, Kanno E, Bossi G, Booth S, Daniele T, Santoro A, et al. Slp1 and Slp2-a localize to the plasma membrane of CTL and contribute to secretion from the immunological synapse. Traffic. 2008;9:446-57 pubmed publisher, we screened for expression of the synaptotagmin-like proteins (Slps): Slp1/JFC1, Slp2-a/exophilin4, Slp3-a, Slp4/granuphilin, Slp5 and rabphilin in CTL. We found that both Slp1 and Slp2-a are expressed in CTL...