scholarly journals Molecular basis of cholesterol efflux via ABCG subfamily transporters

2021 ◽  
Vol 118 (34) ◽  
pp. e2110483118
Author(s):  
Yingyuan Sun ◽  
Jin Wang ◽  
Tao Long ◽  
Xiaofeng Qi ◽  
Linda Donnelly ◽  
...  
Keyword(s):  
Abc Transporters ◽  
Binding Sites ◽  
Molecular Basis ◽  
Cholesterol Efflux ◽  
Bound States ◽  
High Density Lipoproteins ◽  
Cellular Cholesterol ◽  
Nucleotide Binding Sites ◽  
Cholesterol Levels ◽  
Neutral Sterols

The ABCG1 homodimer (G1) and ABCG5–ABCG8 heterodimer (G5G8), two members of the adenosine triphosphate (ATP)–binding cassette (ABC) transporter G family, are required for maintenance of cellular cholesterol levels. G5G8 mediates secretion of neutral sterols into bile and the gut lumen, whereas G1 transports cholesterol from macrophages to high-density lipoproteins (HDLs). The mechanisms used by G5G8 and G1 to recognize and export sterols remain unclear. Here, we report cryoelectron microscopy (cryo-EM) structures of human G5G8 in sterol-bound and human G1 in cholesterol- and ATP-bound states. Both transporters have a sterol-binding site that is accessible from the cytosolic leaflet. A second site is present midway through the transmembrane domains of G5G8. The Walker A motif of G8 adopts a unique conformation that accounts for the marked asymmetry in ATPase activities between the two nucleotide-binding sites of G5G8. These structures, along with functional validation studies, provide a mechanistic framework for understanding cholesterol efflux via ABC transporters.

Binding of modified high density lipoproteins to endothelial cells: relation with cellular cholesterol efflux?

1992 ◽  
Vol 97 (2-3) ◽  
pp. 131-142 ◽  
Author(s):  
Elisabeth P.C. Kilsdonk ◽  
Teus van Gent ◽  
Amelia N.R.D. Dorsman ◽  
Arie van Tol
Keyword(s):  
Endothelial Cells ◽  
Cholesterol Efflux ◽  
High Density ◽  
High Density Lipoproteins ◽  
Cellular Cholesterol ◽  
Cellular Cholesterol Efflux

scholarly journals Cellular cholesterol efflux is modulated by phospholipid-derived signaling molecules in familial HDL deficiency/Tangier disease fibroblasts

2001 ◽  
Vol 42 (2) ◽  
pp. 249-257 ◽  
Author(s):  
Bassam Haidar ◽  
Stephanie Mott ◽  
Betsie Boucher ◽  
Ching Yin Lee ◽  
Michel Marcil ◽  
...  
Keyword(s):  
Cholesterol Efflux ◽  
Signaling Molecules ◽  
Tangier Disease ◽  
Cellular Cholesterol ◽  
Cellular Cholesterol Efflux

scholarly journals A Modified Autonomous En Transposon in Maize (Zea mays L.) Elicits a Differential Response of Reporter Alleles

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1329-1338
Author(s):  
Peter A Peterson
Keyword(s):  
Molecular Structure ◽  
Binding Sites ◽  
Molecular Basis ◽  
Zea Mays L ◽  
Phenotypic Expression ◽  
Terminal Inverted Repeat ◽  
Coding Sequences ◽  
Defective Element ◽  
Related Element ◽  
Unstable Genes

Transposable elements in maize are composed of a defined molecular structure that includes coding sequences, determiners of functionality and ordered terminal motifs that provide binding sites for transposase proteins. Alterations in these components change the phenotypic expression of unstable genes with transposon inserts. The molecular basis for the altered timing and frequency of transposition as determined by the size and number of spots on kernels or stripes on leaves has generally been described for defective inserts in genes. Most differential patterns can be ascribed to alterations in the terminal motifs of the reporter allele structure that supplies a substrate (terminal inverted repeat motifs) for transposase activity. For autonomously functioning alleles, the explanations for changes in phenotype are not so clear. In this report, an En-related element identified as F-En is described that shares with En the recognition of a specific defective element c1(mr)888104 but differs from En in that this F-En element does not recognize the canonical c1(mr) elements that are recognized by En. Evidence is provided suggesting that F-En does not recognize other En/Spm-related defective elements, some of whose sequences are known. This modified En arose from a c1-m autonomously mutating En allele.

Sign in / Sign up

Export Citation Format

Share Document