Eur. J. Entomol. 122: 189-197, 2025 | DOI: 10.14411/eje.2025.024

Localization of SNAP-29 and Syntaxin 6 in the brain of Bombyx moriOriginal article

Fumika TORYU1, Yuto SAITOH1, Kengo KANAMARU ORCID...1, Katsuhiko SAKAMOTO ORCID...1, Yuichi UNO ORCID...2, Tomohide UNO ORCID...1, *
1 Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan; e-mails: f3104z1@gmail.com (F.T.), ksakamoto@diamond.kobe-u.ac.jp, unotom@kobe-u.ac.jp
2 Department of Plant Resource Science, Faculty of Agriculture, Kobe University, Nada-ku, Hyogo 657-8501, Japan

Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are a family of small conserved eukaryotic proteins that mediate fusion between organelles and the plasma membrane. Prior to fusion, complementary SNAREs, such as syntaxin, synaptosome-associated protein (SNAP), and synaptobrevin, assemble between membranes with the aid of accessory proteins that provide a scaffold to initiate SNARE zippering, pulling the membranes together, and mediating fusion. SNAP-29 and Syntaxin 6 from Bombyx mori were expressed in Escherichia coli and purified using affinity chromatography. We then produced antibodies against SNAP-29, and Syntaxin 6 of Bombyx mori in rabbits, which were used for immunohistochemistry. Immunohistochemistry results revealed that the expression of SNAP-29 was restricted to neurons in the pars intercerebralis (PI) and dorsolateral protocerebrum (DL) of the brain. The amount of SNAP-29 in the brain increases with hunger. Syntaxin 6 was restricted to neurons in the PI, the central complex (CX) and ventro-median protocerebrum (VP). SNAP-29 co-localized with SNAP-25 and Syntaxin 1A in the PI, and with Syntaxin 1A in the DL. Syntaxin 6 co-localized with SNAP-25 and Syntaxin 1A in the PI and with SNAP-25 in the CX. Bombyxin-immunopositive neurons of the brain occurred in SNAP-29 and Syntaxin 6-IRs. PTTH- and period-immunopositive neurons of the brain occurred in SNAP-29-IRs. Syntaxin 6 is present in EH secretory neurons of the brain.

Keywords: Lepidoptera, Bombycidae, insect, SNAREs, neuropeptide, neurohormone, starvation

Received: March 17, 2025; Revised: June 26, 2025; Accepted: June 26, 2025; Published online: August 22, 2025  Show citation

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TORYU, F., SAITOH, Y., KANAMARU, K., SAKAMOTO, K., UNO, Y., & UNO, T. (2025). Localization of SNAP-29 and Syntaxin 6 in the brain of Bombyx mori. EJE, 122, Article 189-197. https://doi.org/10.14411/eje.2025.024
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    References

    1. Agui N., Granger N.A., Gilbert L.I. & Bollenbacher W.E. 1979: Cellular localization of the insect prothoracicotropic hormone: In vitro assay of a single neurosecretory cell. - Proc. Natl. Acad. Sci. U.S.A. 76: 5694-5698. Go to original source...
    2. Chernomordik L.V. & Kozlov M.M. 2005: Membrane hemifusion: crossing a chasm in two leaps. - Cell 123: 375-382. Go to original source...
    3. Cui L., Li H., Xi Y., Hu Q., Liu H., Fan J., Xiang Y., Zhang X., Shui W. & Lai Y. 2022: Vesicle trafficking and vesicle fusion: mechanisms, biological functions, and their implications for potential disease therapy. - Mol. Biomed. 3(1): 29, 33 pp. Go to original source...
    4. Hamasaki M., Furuta N., Matsuda A., Nezu A., Yamamoto A., Fujita N., Oomori H., Noda T., Haraguchi T., Hiraoka Y. et al. 2013: Autophagosomes form at ER-mitochondria contact sites. - Nature 495: 389-393. Go to original source...
    5. Han J., Pluhackova K. & Böckmann R.A. 2017: The multifaceted role of SNARE proteins in membrane fusion. - Front. Physiol. 8: 5, 17 pp. Go to original source...
    6. Heinze S. & Reppert S.M. 2012: Anatomical basis of sun compass navigation I: the general layout of the monarch butterfly brain. - J. Comp. Neurol. 520: 1599-1628. Go to original source...
    7. Houy S., Croisé P., Gubar O., Chasserot-Golaz S., Tryoen-Tóth P., Bailly Y., Ory S., Bader M.F. & Gasman S. 2013: Exocytosis and endocytosis in neuroendocrine cells: inseparable membranes! - Front. Endocrinol. 4: 135, 6 pp. Go to original source...
    8. Hoyer D. & Bartfai T. 2012: Neuropeptides and neuropeptide receptors: drug targets, and peptide and non-peptide ligands: a tribute to Prof. Dieter Seebach. - Chem. Biodivers. 9: 2367-2387. Go to original source...
    9. Iwai S., Thi Dieu Trang L., Sehadova H. & Takeda M. 2008: Expression analyses of casein kinase 2alpha and casein kinase 2beta in the silkmoth, Bombyx mori. - Comp. Biochem. Physiol. (B) 149: 38-46. Go to original source...
    10. Jung J.J., Inamdar S.M., Tiwari A. & Choudhury A. 2012: Regulation of intracellular membrane trafficking and cell dynamics by syntaxin-6. - Biosci. Rep. 32: 383-391. Go to original source...
    11. Kamito T., Tanaka H., Sato B., Nagasawa H. & Suzuki A. 1992: Nucleotide sequence of cDNA for the eclosion hormone of the silkworm, Bombyx mori, and the expression in a brain. - Biochem. Biophys. Res. Commun. 182: 514-519. Go to original source...
    12. Kono T., Nagasawa H., Kataoka H., Isogai A., Fugo H. & Suzuki A. 1990: Eclosion hormone of the silkworm Bombyx mori. Expression in Escherichia coli and location of disulfide bonds. - FEBS Lett. 263: 358-360. Go to original source...
    13. Laemmli U.K. 1970: Cleavage of structural proteins during the assembly of the head of bacteriophage T4. - Nature 227: 680-685. Go to original source...
    14. Mizoguchi A. & Okamoto N. 2013: Insulin-like and IGF-like peptides in the silkmoth Bombyx mori: discovery, structure, secretion, and function. - Front. Physiol. 4: 217, 11 pp. Go to original source...
    15. Mizoguchi A., Ishizaki H., Nagasawa H., Kataoka H., Isogai A., Tamura S., Suzuki A., Fujino M. & Kitada C. 1987: A monoclonal antibody against a synthetic fragment of bombyxin (4K-prothoracicotropic hormone) from the silkmoth, Bombyx mori: characterization and immunohistochemistry. - Mol. Cell. Endocrinol. 51: 227-235. Go to original source...
    16. Mizoguchi A., Dedos S.G., Fugo H. & Kataoka H. 2002: Basic pattern of fluctuation in hemolymph PTTH titers during larval-pupal and pupal-adult development of the silkworm, Bombyx mori. - Gen. Comp. Endocrinol. 127: 181-189. Go to original source...
    17. Nagasawa H., Kataoka H., Isogai A., Tamura S., Suzuki A., Mizoguchi A., Fujiwara Y., Takahashi S.Y. & Ishizaki H. 1986: Amino acid sequence of a prothoracicotropic hormone of the silkworm Bombyx mori. - Proc. Natl. Acad. Sci. U.S.A. 83: 5840-5843. Go to original source...
    18. Nagata S., Kataoka H. & Suzuki A. 2005: Silk moth neuropeptide hormones: prothoracicotropic hormone and others. - Ann. N.Y. Acad. Sci. 1040: 38-52. Go to original source...
    19. Nassel D.R. & Homberg U. 2006: Neuropeptides in interneurons of the insect brain. - Cell Tissue Res. 326: 1-24. Go to original source...
    20. Nassel D.R. & Winther A.M. 2010: Drosophila neuropeptides in regulation of physiology and behavior. - Prog. Neurobiol. 92: 42-104. Go to original source...
    21. Nijhout H.F. & Grunert L.W. 2002: Bombyxin is a growth factor for wing imaginal disks in Lepidoptera. - Proc. Natl. Acad. Sci. U.S.A. 99: 15446-15450. Go to original source...
    22. Nijhout H.F., Smith W.A., Schachar I., Subramanian S., Tobler A. & Grunert L.W. 2007: The control of growth and differentiation of the wing imaginal disks of Manduca sexta. - Dev. Biol. 302: 569-576. Go to original source...
    23. O'Brien M.A., Katahira E.J., Flanagan T.R., Arnold L.W., Haughton G. & Bollenbacher W.E. 1988: A monoclonal antibody to the insect prothoracicotropic hormone. - J. Neurosci. 8: 3247-3257. Go to original source...
    24. Pan P.Y., Cai Q., Lin L., Lu P.H., Duan S. & Sheng Z.H. 2005: SNAP-29-mediated modulation of synaptic transmission in cultured hippocampal neurons. - J. Biol. Chem. 280: 25769-25779. Go to original source...
    25. Pelham H.R. 2001: SNAREs and the specificity of membrane fusion. - Trends Cell Biol. 11: 99-101. Go to original source...
    26. Riddiford L.M., Hewes R.S. & Truman J.W. 1994: Dynamics and metamorphosis of an identifiable peptidergic neuron in an insect. - J. Neurobiol. 25: 819-830. Go to original source...
    27. Roller L., Yamanaka N., Watanabe K., Daubnerova I., Zitnan D., Kataoka H. & Tanaka Y. 2008: The unique evolution of neuropeptide genes in the silkworm Bombyx mori. - Insect Biochem. Mol. Biol. 38: 1147-1157. Go to original source...
    28. Sasao M., Uno T., Kitagawa R., Matsui A., Toryu F., Mizoguchi A., Kanamaru K., Sakamoto K. & Uno Y. 2023: Localization of SNARE proteins in the brain and corpus allatum of Bombyx mori. - Histochem. Cell. Biol. 159: 199-208. Go to original source...
    29. Sauman I. & Reppert S.M. 1996: Molecular characterization of prothoracicotropic hormone (PTTH) from the giant silkmoth Antheraea pernyi: developmental appearance of PTTH-expressing cells and relationship to circadian clock cells in central brain. - Dev. Biol. 178: 418-429. Go to original source...
    30. Shin O.H. 2014: Exocytosis and synaptic vesicle function. - Comp. Physiol. 4: 149-175. Go to original source...
    31. Steegmaier M., Yang B., Yoo J.S., Huang B., Shen M., Yu S., Luo Y. & Scheller R.H. 1998: Three novel proteins of the syntaxin/SNAP-25 family. - J. Biol. Chem. 273: 34171-34179. Go to original source...
    32. Su Q., Mochida S., Tian J.H., Mehta R. & Sheng Z.H. 2001: SNAP-29: a general SNARE protein that inhibits SNARE disassembly and is implicated in synaptic transmission. - Proc. Natl. Acad. Sci. U.S.A. 98: 14038-14043. Go to original source...
    33. Südhof T.C. & Rothman J.E. 2009: Membrane fusion: grappling with SNARE and SM proteins. - Science 323: 474-477. Go to original source...
    34. Takáts S. & Juhász G. 2013: A genetic model with specifically impaired autophagosome-lysosome fusion. - Autophagy 9: 1251-1252. Go to original source...
    35. Takamori S., Holt M., Stenius K., Lemke E.A., Grønborg M., Riedel D., Urlaub H., Schenck S., Brügger B., Ringler P. et al. 2006: Molecular anatomy of a trafficking organelle. - Cell 127: 831-846. Go to original source...
    36. Takáts S., Nagy P., Varga Á., Pircs K., Kárpáti M., Varga K., Kovács A.L., Hegedûs K. & Juhász G. 2013: Autophagosomal Syntaxin17-dependent lysosomal degradation maintains neuronal function in Drosophila. - J. Cell Biol. 201: 531-539. Go to original source...
    37. Thummel C.S. 2002: Ecdysone-regulated puff genes 2000. - Insect Biochem. Mol. Biol. 32: 113-120. Go to original source...
    38. Tian X., Teng J. & Chen J. 2021: New insights regarding SNARE proteins in autophagosome-lysosome fusion. - Autophagy 17: 2680-2688. Go to original source...
    39. Tobe S.S. & Pratt G.E. 1974: Dependence of juvenile hormone release from corpus allatum on intraglandular content. - Nature 252: 474-476. Go to original source...
    40. Truman J.W. & Riddiford L.M. 1970: Neuroendocrine control of ecdysis in silkmoths. - Science 167: 1624-1626. Go to original source...
    41. Truman J.W. & Sokolove P.G. 1972: Silk moth eclosion: hormonal triggering of a centrally programmed pattern of behavior. - Science 175: 1491-1493. Go to original source...
    42. Uno T., Nakada T., Okamaoto S., Nakamura M., Matsubara M., Imaishi H., Yamagata H., Kanamaru K. & Takagi M. 2007: Determination of phosphorylated amino acid residues of Rab8 from Bombyx mori. - Arch. Insect Biochem. Physiol. 66: 89-97. Go to original source...
    43. Uno T., Hata K., Hiragaki S., Isoyama Y., Trang le T.D., Uno Y., Kanamaru K., Yamagata H., Nakamura M., Takagi M. et al. 2010: Small GTPases of the Rab family in the brain of Bombyx mori. - Histochem. Cell Biol. 134: 615-622. Go to original source...
    44. Uno T., Isoyama Y., Sakamoto K., Uno Y., Sakamoto K., Kanamaru K., Yamagata H., Takagi M., Mizoguchi A. & Takeda M. 2014: Characterization of Rab-interacting lysosomal protein in the brain of Bombyx mori. - Histochem. Cell Biol. 141: 311-320. Go to original source...
    45. Urbina F.L. & Gupton S.L. 2020: SNARE-mediated exocytosis in neuronal development. - Front. Mol. Neurosci. 13: 133, 17 pp. Go to original source...
    46. Van de Velde S., Badisco L., Claeys I., Verleyen P., Chen X., Vanden Bosch L., Vanden Broeck J. & Smagghe G. 2007: Insulin-like peptides in Spodoptera littoralis (Lepidoptera): Detection, localization and identification. - Gen. Comp. Endocrinol. 153: 72-79. Go to original source...
    47. Xu H., Mohtashami M., Stewart B., Boulianne G. & Trimble W.S. 2014: Drosophila SNAP-29 is an essential SNARE that binds multiple proteins involved in membrane traffic. - PLoS ONE 9(3): e91471, 8 pp. Go to original source...
    48. Xu G., Teng Z.W., Gu G.X., Qi Y.X., Guo L., Xiao S., Wang F., Fang Q., Wang F., Song Q.S. et al. 2020: Genome-wide characterization and transcriptomic analyses of neuropeptides and their receptors in an endoparasitoid wasp, Pteromalus puparum. - Arch. Insect Biochem. Physiol. 103(2):e21625, 23 pp. Go to original source...
    49. Yan C., Jiang J., Yang Y., Geng X. & Dong W. 2022: The function of VAMP2 in mediating membrane fusion: An overview. - Front. Mol. Neurosci. 15: 948160, 15 pp. Go to original source...
    50. Zavodska R., Sauman I. & Sehnal F. 2003: Distribution of PER protein, pigment-dispersing hormone, prothoracicotropic hormone, and eclosion hormone in the cephalic nervous system of insects. - J. Biol. Rhythms 18: 106-122. Go to original source...
    51. Zeng H., Qin Y., Du E., Wei Q., Li Y., Huang D., Wang G., Veenstra J.A., Li S. & Li N. 2020: Genomics- and peptidomics-based discovery of conserved and novel neuropeptides in the American cockroach. - J. Proteome Res. 20: 1217-1228. Go to original source...

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