Subcellular distribution of chromogranins A and B in bovine adrenal chromaffin cells.
The major secretory granule proteins chromogranins A (CGA) and B (CGB) have recently been shown to play critical roles in inositol 1,4,5-trisphosphate-dependent intracellular Ca(2+) mobilizations. We determined here the subcellular distribution of CGA and CGB based on 3D-images of chromaffin cells, and found that approximately 95% of cellular CGA was present in secretory granules while approximately 5% was in the endoplasmic reticulum (ER), whereas approximately 57% of cellular CGB was in secretory granules while approximately 24% and approximately 19% were in the ER and nucleus, respectively. These results suggest that chromogranins are at the center of intracellular Ca(2+) homeostasis in secretory cells.
Huh
Yang Hoon
YH
National Creative Research Initiative Center for Secretory Granule Research, and Department of Biochemistry, Inha University College of Medicine, Jung Gu, Incheon 400-712, Republic of Korea.
Bahk
Sook Jin
SJ
Ghee
Jung Yeon
JY
Yoo
Seung Hyun
SH
D000311:Adrenal Glands / Q000166:cytology*; D000818:Animals; D002417:Cattle; D002467:Cell Nucleus / Q000737:chemistry; D019439:Chromaffin Cells / Q000737:chemistry* / Q000648:ultrastructure; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis*; D004721:Endoplasmic Reticulum / Q000737:chemistry; D021621:Imaging, Three-Dimensional; D007150:Immunohistochemistry; D009479:Neuropeptides / Q000032:analysis*; D015388:Organelles / Q000737:chemistry / Q000648:ultrastructure; D022142:Secretory Vesicles / Q000737:chemistry*
D053379:Chromogranin A; D002864:Chromogranins; D009479:Neuropeptides