Presence of syntaxin 1A in secretory granules of chromaffin cells and interaction with chromogranins A and B.
Syntaxin 1A and synaptotagmin I are key participants of fusion complex formation during exocytotic processes, and syntaxin 1A is known to be present in the plasma membrane. Here, we show the presence of not only synaptotagmin I but also syntaxin 1A in secretory granules of bovine adrenal chromaffin cells by immunogold electron microscopy, and further demonstrate the interaction of these proteins with chromogranins A and B (CGA and CGB), two major proteins of secretory granules. Interaction between chromogranins and the components of fusion complex also suggests active participation of CGA and CGB in fusion complex formation and subsequent exocytosis.
Yoo
Seung Hyun
SH
Department of Biochemistry, National Creative Research Initiative Center for Secretory Granule Research, Inha University College of Medicine, Jung Gu, Incheon 400-712, Republic of Korea. shyoo@inha.ac.kr
You
Soon Hee
SH
Huh
Yang Hoon
YH
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis* / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000378:metabolism; D002417:Cattle; D019439:Chromaffin Cells / Q000737:chemistry* / Q000378:metabolism*; D053379:Chromogranin A; D002864:Chromogranins / Q000378:metabolism*; D005089:Exocytosis / Q000502:physiology; D008562:Membrane Glycoproteins / Q000032:analysis / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000378:metabolism*; D009687:Nuclear Proteins / Q000032:analysis / Q000378:metabolism; D022142:Secretory Vesicles / Q000737:chemistry* / Q000378:metabolism; D050863:Synaptotagmin I; D050857:Synaptotagmins; D050827:Syntaxin 1
D000954:Antigens, Surface; D002135:Calcium-Binding Proteins; D053379:Chromogranin A; D002864:Chromogranins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D050863:Synaptotagmin I; D050827:Syntaxin 1; D050857:Synaptotagmins