TY - JOUR
T1 - ER-to-Golgi transport in hela cells displays high resilience to Ca2+ and energy stresses
AU - Rauter, Thomas
AU - Burgstaller, Sandra
AU - Gottschalk, Benjamin
AU - Ramadani-Muja, Jeta
AU - Bischof, Helmut
AU - Hay, Jesse C.
AU - Graier, Wolfgang F.
AU - Malli, Roland
N1 - Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020/10
Y1 - 2020/10
N2 - One third of all human proteins are either transmembrane or soluble secretory proteins that first target the endoplasmic reticulum (ER). These proteins subsequently leave the ER and enter the Golgi apparatus via ER-Golgi intermediate vesicular structures. Live-cell imaging of cargos fused to fluorescent proteins (FPs) enables the high-resolution visualization and characterization of secretory transport processes. Here, we performed fluorescence time-lapse imaging to assess the Ca2+ and energy dependency of ER-to-Golgi transport in living HeLa cells, a cancer cell model which has been well investigated. Our data revealed that ER-to-Golgi transport remained highly efficient in the absence of ATP-generating substrates, despite clear reductions in cytosolic and mitochondrial ATP levels under these energy stress conditions. However, cell treatment with 2-deoxy-D-glucose (2-DG), which severely diminished subcellular ATP levels, abolished ER-to-Golgi transport. Interestingly, while 2-DG elevated cytosolic Ca2+ levels and reduced long-distance movements of glycosylphosphatidylinositol (GPI)-positive vesicles, robust short-term ER Ca2+ mobilizations, which strongly affected the motility of these vesicles, did not considerably impair ER-to-Golgi transport. In summary, we highlight that ER-to-Golgi transport in HeLa cells remains functional despite high energy and Ca2+ stress levels.
AB - One third of all human proteins are either transmembrane or soluble secretory proteins that first target the endoplasmic reticulum (ER). These proteins subsequently leave the ER and enter the Golgi apparatus via ER-Golgi intermediate vesicular structures. Live-cell imaging of cargos fused to fluorescent proteins (FPs) enables the high-resolution visualization and characterization of secretory transport processes. Here, we performed fluorescence time-lapse imaging to assess the Ca2+ and energy dependency of ER-to-Golgi transport in living HeLa cells, a cancer cell model which has been well investigated. Our data revealed that ER-to-Golgi transport remained highly efficient in the absence of ATP-generating substrates, despite clear reductions in cytosolic and mitochondrial ATP levels under these energy stress conditions. However, cell treatment with 2-deoxy-D-glucose (2-DG), which severely diminished subcellular ATP levels, abolished ER-to-Golgi transport. Interestingly, while 2-DG elevated cytosolic Ca2+ levels and reduced long-distance movements of glycosylphosphatidylinositol (GPI)-positive vesicles, robust short-term ER Ca2+ mobilizations, which strongly affected the motility of these vesicles, did not considerably impair ER-to-Golgi transport. In summary, we highlight that ER-to-Golgi transport in HeLa cells remains functional despite high energy and Ca2+ stress levels.
KW - Cancer cell metabolism
KW - Cellular calcium homeostasis
KW - Coat protein complex II (COPII) vesicles
KW - ER-to-Golgi transport
KW - Fluorescent protein technology
KW - Live-cell imaging
KW - Protein transport and sorting
KW - Secretory pathway
KW - Subcellular ATP imaging
KW - Vesicle trafficking
UR - http://www.scopus.com/inward/record.url?scp=85094221083&partnerID=8YFLogxK
U2 - 10.3390/cells9102311
DO - 10.3390/cells9102311
M3 - Article
C2 - 33080790
AN - SCOPUS:85094221083
SN - 2073-4409
VL - 9
SP - 1
EP - 26
JO - Cells
JF - Cells
IS - 10
M1 - 2311
ER -