Reconstituted low density lipoprotein: A vehicle for the delivery of hydrophobic fluorescent probes to cells

Krieger, Monty; Smith, Louis C.; Anderson, R. G.; Goldstein, Joseph L.; Kao, Yin J.; Pownall, Henry J.; Gotto, Antonio M.; Brown, Michael S.

doi:10.1002/jss.400100409

Cited by 101 publications

(41 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In humans, these endocytic receptors bind hydrophobic molecules (84) and participate in a wide range of physiological processes. Some members of this family have also multiligand-binding properties (85,86).…”

Section: Discussionmentioning

confidence: 99%

A link between host plant adaptation and pesticide resistance in the polyphagous spider mite Tetranychus urticae

Dermauw

Wybouw

Rombauts

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

373

475

View full text Add to dashboard Cite

Plants produce a wide range of allelochemicals to defend against herbivore attack, and generalist herbivores have evolved mechanisms to avoid, sequester, or detoxify a broad spectrum of natural defense compounds. Successful arthropod pests have also developed resistance to diverse classes of pesticides and this adaptation is of critical importance to agriculture. To test whether mechanisms to overcome plant defenses predispose the development of pesticide resistance, we examined adaptation of the generalist two-spotted spider mite, Tetranychus urticae, to host plant transfer and pesticides. T. urticae is an extreme polyphagous pest with more than 1,100 documented hosts and has an extraordinary ability to develop pesticide resistance. When mites from a pesticidesusceptible strain propagated on bean were adapted to a challenging host (tomato), transcriptional responses increased over time with ∼7.5% of genes differentially expressed after five generations. Whereas many genes with altered expression belonged to known detoxification families (like P450 monooxygenases), new gene families not previously associated with detoxification in other herbivores showed a striking response, including ring-splitting dioxygenase genes acquired by horizontal gene transfer. Strikingly, transcriptional profiles of tomato-adapted mites resembled those of multipesticide-resistant strains, and adaptation to tomato decreased the susceptibility to unrelated pesticide classes. Our findings suggest key roles for both an expanded environmental response gene repertoire and transcriptional regulation in the life history of generalist herbivores. They also support a model whereby selection for the ability to mount a broad response to the diverse defense chemistry of plants predisposes the evolution of pesticide resistance in generalists.genetic variation | lipocalin | transcriptome | major facilitator superfamily | xenosensors

show abstract

Section: Discussionmentioning

confidence: 99%

A link between host plant adaptation and pesticide resistance in the polyphagous spider mite Tetranychus urticae

Dermauw

Wybouw

Rombauts

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

373

475

View full text Add to dashboard Cite

show abstract

“…LDL labeled with 3-pyrenemethyl-23,24-dinor-5-cholen-22-oate-3␤-yl oleate (PMCA oleate, a fluorescent analogue of cholesteryl ester) was prepared as described (20).…”

Section: Methodsmentioning

confidence: 99%

Failure to Cleave Sterol Regulatory Element-binding Proteins (SREBPs) Causes Cholesterol Auxotrophy in Chinese Hamster Ovary Cells with Genetic Absence of SREBP Cleavage-activating Protein

Rawson

Debose-Boyd²,

Goldstein

et al. 1999

Journal of Biological Chemistry

Self Cite

161

163

View full text Add to dashboard Cite

We describe a line of mutant Chinese hamster ovary cells, designated SRD-13A, that cannot cleave sterol regulatory element-binding proteins (SREBPs) at site 1, due to mutations in the gene encoding SREBP cleavageactivating protein (SCAP). The SRD-13A cells were obtained by two rounds of ␥-irradiation followed first by selection for a deficiency of low density lipoprotein receptors and second for cholesterol auxotrophy. In the SRD-13A cells, the only detectable SCAP allele encodes a truncated nonfunctional protein. In the absence of SCAP, the site 1 protease fails to cleave SREBPs, and their transcriptionally active NH 2 -terminal fragments cannot enter the nucleus. As a result, the cells manifest a marked reduction in the synthesis of cholesterol and its uptake from low density lipoproteins. The SRD-13A cells grow only when cholesterol is added to the culture medium. SREBP cleavage is restored and the cholesterol requirement is abolished when SRD-13A cells are transfected with expression vectors encoding SCAP. These results provide formal proof that SCAP is essential for the cleavage of SREBPs at site 1. Sterol regulatory element-binding proteins (SREBPs)1 are membrane-bound transcription factors whose active fragments are released from membranes by controlled proteolysis in order to activate the synthesis of cholesterol and unsaturated fatty acids and their uptake from plasma lipoprotein (1). SREBP cleavage-activating protein (SCAP) is a membrane-bound regulatory protein that forms a complex with SREBPs and facilitates proteolytic release of the active fragments (2, 3). SCAP contains a sterol-sensing domain that allows sterols to suppress SREBP cleavage, thereby mediating feedback suppression of lipid synthesis and uptake (4, 5).The SREBPs are tripartite proteins that are embedded in membranes of the endoplasmic reticulum (ER) and nuclear envelope in a hairpin orientation (1). The transcriptionally active NH 2 -terminal segment of ϳ480 amino acids projects into the cytosol. This segment contains a basic helix-loop-helixleucine zipper sequence that allows the protein to dimerize, to bind DNA, and to recruit transcriptional coactivators (6, 7). The NH 2 -terminal segment is followed by a 90-amino acid membrane attachment segment that consists of two membrane-spanning helices separated by a short hydrophilic loop of 31 amino acids that projects into the lumen of the ER and nuclear envelope. The third segment of the SREBP comprises ϳ590 amino acids that project into the cytosol, where they form a complex with SCAP. This segment has been called the regulatory domain (1).SCAP is a polytopic membrane protein of 1276 amino acids that has two distinct domains. The NH 2 -terminal domain of ϳ730 amino acids consists of eight transmembrane helices separated by hydrophilic loops (5). Transmembrane helices 2-6 have been designated the sterol-sensing domain (5). This domain resembles sequences in three other proteins that are postulated to interact with sterols: 3-hydroxy-3-methylglutaryl CoA reductase, the Niemann-Pick C1 pr...

show abstract

“…LDL (PMCA-O LDL) was synthesized by reconstituting the lipid core of LDL with PMCA-O as described (45), with minor modifications. After reconstitution with PMCA-O, fluorescently labeled LDL monomers were separated from aggregated LDL via FPLC using a Superose 6 column.…”

Section: Figurementioning

confidence: 99%

Disruption of LDL but not VLDL clearance in autosomal recessive hypercholesterolemia

Jones¹,

Garuti²,

Michaely³

et al. 2007

J. Clin. Invest.

View full text Add to dashboard Cite

Genetic defects in LDL clearance result in severe hypercholesterolemia and premature atherosclerosis. Mutations in the LDL receptor (LDLR) cause familial hypercholesterolemia (FH), the most severe form of genetic hypercholesterolemia. A phenocopy of FH, autosomal recessive hypercholesterolemia (ARH), is due to mutations in an adaptor protein involved in LDLR internalization. Despite comparable reductions in LDL clearance rates, plasma LDL levels are substantially lower in ARH than in FH. To determine the metabolic basis for this difference, we examined the synthesis and catabolism of VLDL in murine models of FH (Ldlr -/-) and ARH (Arh -/-). The hyperlipidemic response to a high-sucrose diet was greatly attenuated in Arh -/-mice compared with Ldlr -/-mice despite similar rates of VLDL secretion. The rate of VLDL clearance was significantly higher in Arh -/-mice than in Ldlr -/-mice, suggesting that LDLR-dependent uptake of VLDL is maintained in the absence of ARH. Consistent with these findings, hepatocytes from Arh -/-mice (but not Ldlr -/-mice) internalized β-migrating VLDL (β-VLDL). These results demonstrate that ARH is not required for LDLR-dependent uptake of VLDL by the liver. The preservation of VLDL remnant clearance attenuates the phenotype of ARH and likely contributes to greater responsiveness to statins in ARH compared with FH.

show abstract

Reconstituted low density lipoprotein: A vehicle for the delivery of hydrophobic fluorescent probes to cells

Cited by 101 publications

References 19 publications

A link between host plant adaptation and pesticide resistance in the polyphagous spider mite Tetranychus urticae

A link between host plant adaptation and pesticide resistance in the polyphagous spider mite Tetranychus urticae

Failure to Cleave Sterol Regulatory Element-binding Proteins (SREBPs) Causes Cholesterol Auxotrophy in Chinese Hamster Ovary Cells with Genetic Absence of SREBP Cleavage-activating Protein

Disruption of LDL but not VLDL clearance in autosomal recessive hypercholesterolemia

Contact Info

Product

Resources

About