Requirement of myosin Vb.Rab11a.Rab11-FIP2 complex in cholesterol-regulated translocation of NPC1L1 to the cell surface.
Niemann-Pick C1-like 1 (NPC1L1) plays a critical role in the enterohepatic absorption of free cholesterol. Cellular cholesterol depletion induces the transport of NPC1L1 from the endocytic recycling compartment to the plasma membrane (PM), and cholesterol replenishment causes the internalization of NPC1L1 together with cholesterol via clathrin-mediated endocytosis. Although NPC1L1 has been characterized, the other proteins involved in cholesterol absorption and the endocytic recycling of NPC1L1 are largely unknown. Most of the vesicular trafficking events are dependent on the cytoskeleton and motor proteins. Here, we investigated the roles of the microfilament and microfilament-associated triple complex composed of myosin Vb, Rab11a, and Rab11-FIP2 in the transport of NPC1L1 from the endocytic recycling compartment to the PM. Interfering with the dynamics of the microfilament by pharmacological treatment delayed the transport of NPC1L1 to the cell surface. Meanwhile, inactivation of any component of the myosin Vb.Rab11a.Rab11-FIP2 triple complex inhibited the export of NPC1L1. Expression of the dominant-negative mutants of myosin Vb, Rab11a, or Rab11-FIP2 decreased the cellular cholesterol uptake by blocking the transport of NPC1L1 to the PM. These results suggest that the efficient transport of NPC1L1 to the PM is dependent on the microfilament-associated myosin Vb.Rab11a.Rab11-FIP2 triple complex.
Chu
Bei-Bei
BB
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
Ge
Liang
L
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
Xie
Chang
C
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
Zhao
Yang
Y
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
Miao
Hong-Hua
HH
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
Wang
Jing
J
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
Li
Bo-Liang
BL
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
Song
Bao-Liang
BL
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
D008841:Actin Cytoskeleton / Q000737:chemistry; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism*; D004705:Endocytosis; D005799:Genes, Dominant; D008565:Membrane Proteins / Q000737:chemistry*; D026901:Membrane Transport Proteins / Q000737:chemistry*; D008954:Models, Biological; D009218:Myosins / Q000737:chemistry*; D021381:Protein Transport; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D020691:rab GTP-Binding Proteins / Q000737:chemistry*; D000099193:rab11 GTP-Binding Proteins
D002352:Carrier Proteins; D002784:Cholesterol; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D009218:Myosins; D034741:RNA, Small Interfering; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C101826:Myo5b protein, rat; C482444:NPC1L1 protein, rat; C543424:Rab11fip2 protein, rat