STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma membrane, ER, and ERC

J. Garbarino, M. H. Pan, H. F. Chin, F. W. Lund, F. R. Maxfield, J. L. Breslow

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

STARD4, a member of the evolutionarily conserved START gene family, has been implicated in the non-vesicular intracellular transport of cholesterol. However, the direction of transport and the membranes with which this protein interacts are not clear. We present studies of STARD4 function using small hairpin RNA knockdown technology to reduce STARD4 expression in HepG2 cells. In a cholesterol-poor environment, we found that a reduction in STARD4 expression leads to retention of cholesterol at the plasma membrane, reduction of endoplasmic reticulum-associated cholesterol, and decreased ACAT synthesized cholesteryl esters. Furthermore, D4 KD cells exhibited a reduced rate of sterol transport to the endocytic recycling compartment after cholesterol repletion. Although these cells displayed normal endocytic trafficking in cholesterol-poor and replete conditions, cell surface low density lipoprotein receptor (LDLR) levels were increased and decreased, respectively. We also observed a decrease in NPC1 protein expression, suggesting the induction of compensatory pathways to maintain cholesterol balance. These data indicate a role for STARD4 in nonvesicular transport of cholesterol from the plasma membrane and the endocytic recycling compartment to the endoplasmic reticulum and perhaps other intracellular compartments as well. -Garbarino, J., M. Pan, H.F. Chin, F.W. Lund, F.R. Maxfield, and J.L. Breslow. STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma membrane, ER, and ERC. J. Lipid Res. 2012. 53: 2716-2725.
OriginalsprogEngelsk
TidsskriftJournal of Lipid Research
Vol/bind53
Udgave nummer12
Sider (fra-til)2716-2725
Antal sider10
ISSN0022-2275
DOI
StatusUdgivet - 2012

Citer dette

Garbarino, J. ; Pan, M. H. ; Chin, H. F. ; Lund, F. W. ; Maxfield, F. R. ; Breslow, J. L. / STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma membrane, ER, and ERC. I: Journal of Lipid Research. 2012 ; Bind 53, Nr. 12. s. 2716-2725.
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title = "STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma membrane, ER, and ERC",
abstract = "STARD4, a member of the evolutionarily conserved START gene family, has been implicated in the non-vesicular intracellular transport of cholesterol. However, the direction of transport and the membranes with which this protein interacts are not clear. We present studies of STARD4 function using small hairpin RNA knockdown technology to reduce STARD4 expression in HepG2 cells. In a cholesterol-poor environment, we found that a reduction in STARD4 expression leads to retention of cholesterol at the plasma membrane, reduction of endoplasmic reticulum-associated cholesterol, and decreased ACAT synthesized cholesteryl esters. Furthermore, D4 KD cells exhibited a reduced rate of sterol transport to the endocytic recycling compartment after cholesterol repletion. Although these cells displayed normal endocytic trafficking in cholesterol-poor and replete conditions, cell surface low density lipoprotein receptor (LDLR) levels were increased and decreased, respectively. We also observed a decrease in NPC1 protein expression, suggesting the induction of compensatory pathways to maintain cholesterol balance. These data indicate a role for STARD4 in nonvesicular transport of cholesterol from the plasma membrane and the endocytic recycling compartment to the endoplasmic reticulum and perhaps other intracellular compartments as well. -Garbarino, J., M. Pan, H.F. Chin, F.W. Lund, F.R. Maxfield, and J.L. Breslow. STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma membrane, ER, and ERC. J. Lipid Res. 2012. 53: 2716-2725.",
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STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma membrane, ER, and ERC. / Garbarino, J.; Pan, M. H.; Chin, H. F.; Lund, F. W.; Maxfield, F. R.; Breslow, J. L.

I: Journal of Lipid Research, Bind 53, Nr. 12, 2012, s. 2716-2725.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma membrane, ER, and ERC

AU - Garbarino, J.

AU - Pan, M. H.

AU - Chin, H. F.

AU - Lund, F. W.

AU - Maxfield, F. R.

AU - Breslow, J. L.

PY - 2012

Y1 - 2012

N2 - STARD4, a member of the evolutionarily conserved START gene family, has been implicated in the non-vesicular intracellular transport of cholesterol. However, the direction of transport and the membranes with which this protein interacts are not clear. We present studies of STARD4 function using small hairpin RNA knockdown technology to reduce STARD4 expression in HepG2 cells. In a cholesterol-poor environment, we found that a reduction in STARD4 expression leads to retention of cholesterol at the plasma membrane, reduction of endoplasmic reticulum-associated cholesterol, and decreased ACAT synthesized cholesteryl esters. Furthermore, D4 KD cells exhibited a reduced rate of sterol transport to the endocytic recycling compartment after cholesterol repletion. Although these cells displayed normal endocytic trafficking in cholesterol-poor and replete conditions, cell surface low density lipoprotein receptor (LDLR) levels were increased and decreased, respectively. We also observed a decrease in NPC1 protein expression, suggesting the induction of compensatory pathways to maintain cholesterol balance. These data indicate a role for STARD4 in nonvesicular transport of cholesterol from the plasma membrane and the endocytic recycling compartment to the endoplasmic reticulum and perhaps other intracellular compartments as well. -Garbarino, J., M. Pan, H.F. Chin, F.W. Lund, F.R. Maxfield, and J.L. Breslow. STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma membrane, ER, and ERC. J. Lipid Res. 2012. 53: 2716-2725.

AB - STARD4, a member of the evolutionarily conserved START gene family, has been implicated in the non-vesicular intracellular transport of cholesterol. However, the direction of transport and the membranes with which this protein interacts are not clear. We present studies of STARD4 function using small hairpin RNA knockdown technology to reduce STARD4 expression in HepG2 cells. In a cholesterol-poor environment, we found that a reduction in STARD4 expression leads to retention of cholesterol at the plasma membrane, reduction of endoplasmic reticulum-associated cholesterol, and decreased ACAT synthesized cholesteryl esters. Furthermore, D4 KD cells exhibited a reduced rate of sterol transport to the endocytic recycling compartment after cholesterol repletion. Although these cells displayed normal endocytic trafficking in cholesterol-poor and replete conditions, cell surface low density lipoprotein receptor (LDLR) levels were increased and decreased, respectively. We also observed a decrease in NPC1 protein expression, suggesting the induction of compensatory pathways to maintain cholesterol balance. These data indicate a role for STARD4 in nonvesicular transport of cholesterol from the plasma membrane and the endocytic recycling compartment to the endoplasmic reticulum and perhaps other intracellular compartments as well. -Garbarino, J., M. Pan, H.F. Chin, F.W. Lund, F.R. Maxfield, and J.L. Breslow. STARD4 knockdown in HepG2 cells disrupts cholesterol trafficking associated with the plasma membrane, ER, and ERC. J. Lipid Res. 2012. 53: 2716-2725.

U2 - 10.1194/jlr.M032227

DO - 10.1194/jlr.M032227

M3 - Journal article

VL - 53

SP - 2716

EP - 2725

JO - Journal of Lipid Research

JF - Journal of Lipid Research

SN - 0022-2275

IS - 12

ER -