Cellular distribution, levels, and function of the diazepam-binding inhibitor/acyl-CoA-binding protein in last instar Manduca sexta midgut

Snyder, Mark J.; Antwerpen, Rik van

doi:10.1007/s004410050804

Cited by 21 publications

(24 citation statements)

References 32 publications

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“…This indicates that ACBP is expressed in an allele dosage-dependent fashion from both alleles. The immunohistochemical detections revealed that ACBP is distributed evenly in the hepatocytes from ACBP ϩ/ϩ liver and that ACBP is present both in the cytosol and in the nucleus as has been reported for other cell types (57)(58)(59)(60). Importantly, ACBP staining is completely absent from the liver of ACBP Ϫ/Ϫ mice, thereby demonstrating the specificity of the antibody.…”

Section: Resultssupporting

confidence: 71%

Disruption of the Acyl-CoA-binding Protein Gene Delays Hepatic Adaptation to Metabolic Changes at Weaning

Neess¹,

Bloksgaard²,

Bek³

et al. 2011

Journal of Biological Chemistry

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The mouse acyl-CoA-binding protein (ACBP) 5 /diazepam binding inhibitor is a 10-kDa intracellular protein consisting of 86 amino acids. It is highly conserved throughout evolution and expressed in all cell types in the eukaryotes investigated (1, 2). This, together with the characteristics of the ACBP promoter (3, 4), implies a housekeeping function of the gene. However, expression levels vary markedly between tissues (5) and in response to different metabolic stimuli (6 -9), thereby indicating that ACBP might perform more specialized functions in some cell types. The ACBP protein binds C 14 -C 22 acyl-CoA esters with high affinity and specificity (10, 11) and has very little or no affinity toward other ligands (11-13). From in vitro studies, ACBP is known to protect acyl-CoA esters from hydrolysis (14 -16) and to relieve acyl-CoA inhibition of a number of enzymes, including long chain acyl-CoA synthetase, acetyl-CoA carboxylase (ACC), adenine nucleotide translocase, fatty acid synthetase (FAS), carnitine palmitoyltransferase, and acyl-CoA:cholesterol acyltransferase (9, 16 -18). In addition, ACBP is known to donate acyl-CoA esters to phospholipid, glycerolipid, and cholesteryl ester (CE) synthesis (14, 18 -21). Finally, proteolytic products of secreted ACBP have been shown to have signaling functions in Dictyostelium as well as mammalian cells (22). Targeted disruption of the yeast ACBP gene (ACB1) revealed that ACBP deficiency results in increased levels of C18:0 acyl-CoA esters and a decrease in the amount of total C26:0 fatty acids, indicating that transport of FA toward elongation is impaired by lack of ACBP. Furthermore, sphingolipid and ceramide amounts were reduced, membrane structure was altered, and vesicular transport was compromised (23-25).The functions of ACBP in lipid metabolism have been further studied in different mammalian cell culture systems and animal models by both knockdown strategies and overexpression of the protein. It has been reported that knockdown of ACBP by small interfering RNA causes growth arrest and lethality in three different mammalian cell lines (26); however, data from our laboratory show that ACBP can be knocked down in many different cell systems without affecting growth and survival (27). 6 Recently, knockdown of ACBP in HepG2 cells was shown to suppress the expression of a number of genes involved in lipid biosynthesis and lead to decreased levels of saturated and monounsaturated fatty acids (28). In 3T3-L1 preadipocytes, knockdown of ACBP caused a mild impairment of adipocyte differentiation and accumulation of triacylglycerol (TAG) (27), whereas overexpression of ACBP in McA-RH7777 rat hepatoma cells resulted in increased intracellular TAG accumulation (29). Overexpression of ACBP in transgenic mice resulted in accumulation of different lipid classes, including TAG in the liver (30). These results suggest *

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Section: Resultssupporting

confidence: 71%

Disruption of the Acyl-CoA-binding Protein Gene Delays Hepatic Adaptation to Metabolic Changes at Weaning

Neess¹,

Bloksgaard²,

Bek³

et al. 2011

Journal of Biological Chemistry

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“…However, Western blot results also indicated that HaACBP was slightly upregulated during molting and metamorphosis, which was not consistent with the Northern blot results. These results were inconsistent with the expression pattern of ACBP in M. sexta (Synder and Van Antwerpen, 1997) and the housekeeping DBI gene in rats (Kolmer et al, 1993; …”

Section: Discussioncontrasting

confidence: 72%

“…The columnar cells of insects can be divided into 3 regions: apical, central, and basal (Anderson and Harvey, 1966;Davies and King, 1977). The apical region is involved in free fatty acid uptake, and the basal region in diacylglycerol loading onto circulating hemolymph lipoproteins, as described previously (Synder and Van Antwerpen, 1997). This decisively explains why HaACBP is abundantly distributed in the apical and basal regions of columnar cells.…”

Section: Archives Of Insect Biochemistry and Physiology June 2008mentioning

confidence: 87%

Molecular cloning and expression profiles of the acyl‐CoA‐binding protein gene from the cotton bollworm Helicoverpa armigera

Wang

Zhao

2008

Arch Insect Biochem Physiol

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Acyl-CoA-binding protein (ACBP), also known as the diazepam-binding inhibitor (DBI), has been identified in diverse species and is evolutionarily conserved in plants and animals. In a recent study, an ACBP cDNA (HaACBP) encoding 85 amino acids was isolated from the cotton bollworm Helicoverpa armigera. The isolated protein is highly homologous to the ACBP present in the Bombyx mori midgut, where it is highly expressed. Northern and Western blot analyses revealed that HaACBP is expressed predominantly in the midgut. Moreover, Northern blotting revealed that HaACBP was probably stimulated by a high juvenile hormone titer at ecdysis and increased along with feeding at 12 h post-ecdysis. Immunohistochemistry of the midgut revealed that HaACBP is localized in columnar cells. Data from the Northern blotting and immunohistochemistry suggested that HaACBP was expressed during the larval period and is probably responsible for nutrition absorption. However, Western blot analysis of the midgut at different developmental stages indicated that HaACBP was upregulated during larval molting and metamorphosis, which suggested that HaACBP expression was posttranscriptionally regulated.

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“…PG cytosols Were prepared by differential centrifugation methods following homogenization of individual larval PG pools (10±15 PGs per sample) in 20 mM TRIS-HCl (pH 7.2), 1 mM ED-TA, 0.1 mM DTT, and fresh 1 mM PMSF. An enzyme-linked immunosorbant assay (ELISA) was developed to measure cytosol DBI levels according to the procedure of Kingan (1989) using a purified DBI-fusion protein as standard (Snyder and Van Antwerpen 1997) and purified anti-DBI antibody conjugated to alkaline phosphatase (anti-DBI-AP) as antibody.…”

Section: Tissue Expressionmentioning

confidence: 99%

“…Immunohistochemistry AP was conjugated directly to the purified anti-DBI antibodies obtained as described previously (Snyder and Van Antwerpen 1997). The resulting anti-DBI-AP was used at a dilution of 1:10 000 in whole-mount immunocytochemistry of last-instar M. sexta larval PGs.…”

Section: Effects Of Diazepam Agonists and Anti-dbi Antisera On Ecdystmentioning

confidence: 99%

Evidence for a diazepam-binding inhibitor (DBI) benzodiazepine receptor-like mechanism in ecdysteroidogenesis by the insect prothoracic gland

Snyder

Antwerpen

1998

Cell and Tissue Research

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The diazepam-binding inhibitor (DBI) is a 10-kDa highly evolutionarily conserved multifunctional protein. In mammals, one of DBI's functions is in the activation of steroid hormone biosynthesis via binding to a specific outer mitochondrial membrane receptor (benzodiazepine receptor, BZD) and promoting cholesterol transport to the inner membrane. In this work, a multitiered approach was utilized to study the role of this receptor-like activity in ecdysteroidogenesis by larval insect prothoracic glands (PGs). First, both DBI protein and messenger RNA (mRNA) levels were correlated with peak PG ecdysteroid production. In vitro ecdysteroid production was stimulated by the diazepam analogue FGIN 1-27 and inhibited anti-DBI antibodies. The DBI protein was found distributed throughout PG cells, including regions of dense mitochondria, supposed subcellular sites of ecdysteroid synthesis. Finally, a potential mitochondrial BZD receptor in PG cells was demonstrated by photoaffinity labeling. These results suggest an important role for the insect DBI in the stimulation of steroidogenesis by prothoracic glands and indicate that a pathway for cholesterol mobilization leading to the production of steroid hormones appears to be conserved between arthropods and mammals.

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Cellular distribution, levels, and function of the diazepam-binding inhibitor/acyl-CoA-binding protein in last instar Manduca sexta midgut

Cited by 21 publications

References 32 publications

Disruption of the Acyl-CoA-binding Protein Gene Delays Hepatic Adaptation to Metabolic Changes at Weaning

Disruption of the Acyl-CoA-binding Protein Gene Delays Hepatic Adaptation to Metabolic Changes at Weaning

Molecular cloning and expression profiles of the acyl‐CoA‐binding protein gene from the cotton bollworm Helicoverpa armigera

Evidence for a diazepam-binding inhibitor (DBI) benzodiazepine receptor-like mechanism in ecdysteroidogenesis by the insect prothoracic gland

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