Disease relevance of Scp2

• Elevated cholesterol and decreased sterol carrier protein-2 in peroxisomes from AS-30D hepatoma compared to normal rat liver [1].

High impact information on Scp2

• Subcellular localization of sterol carrier protein-2 in rat hepatocytes: its primary localization to peroxisomes [2].
• Molecular cloning and deduced amino acid sequence of nonspecific lipid transfer protein (sterol carrier protein 2) of rat liver: a higher molecular mass (60 kDa) protein contains the primary sequence of nonspecific lipid transfer protein as its C-terminal part [3].
• Two types of cDNA for nonspecific lipid transfer protein (nsLTP), identical to sterol carrier protein 2, of rat liver were cloned; one was 787 base pairs (bp) long containing a 429-bp open reading frame of 143 amino acids, with a mass of 15,303 Da (15-kDa protein) [3].
• Sterol carrier protein-2 overexpression enhances sterol cycling and inhibits cholesterol ester synthesis and high density lipoprotein cholesterol secretion [4].
• Substrate specificities of 3-oxoacyl-CoA thiolase A and sterol carrier protein 2/3-oxoacyl-CoA thiolase purified from normal rat liver peroxisomes. Sterol carrier protein 2/3-oxoacyl-CoA thiolase is involved in the metabolism of 2-methyl-branched fatty acids and bile acid intermediates [5].

Biological context of Scp2

• Extensive screening of rat liver cDNA libraries using rat liver SCP2 cDNA probes led to the isolation of 10 additional clones, all of them containing cDNA insertions longer than 0.8 kb [6].
• Cloning, expression, and nucleotide sequence of rat liver sterol carrier protein 2 cDNAs [6].
• Gene expression of non-specific lipid-transfer protein (nsL-TP; identical with sterol carrier protein 2) and phosphatidylinositol-transfer protein (PI-TP) was investigated in developing rat lung [7].
• Protein kinase C catalyzed phosphorylation of sterol carrier protein 2 [8].
• Prostaglandin F2 alpha mediates ovarian sterol carrier protein-2 expression during luteolysis [9].

Anatomical context of Scp2

• In contrast, ovaries from diabetic animals without fetuses had significantly lower SCP2 levels (p < 0.017) compared to controls [10].
• The mRNAs for other proteins involved in steroid synthesis (sterol carrier protein 2, steroidogenic acute regulatory protein, and P450 side chain cleavage) were detectable in hypothalamus but not affected by estrogen [11].
• Peroxisome proliferator-activated receptor alpha induces rat sterol carrier protein x promoter activity through two peroxisome proliferator-response elements [12].
• Recent data indicate that sterol carrier protein-2 (SCP-2) functions in the rapid movement of newly synthesized cholesterol to the plasma membrane (Puglielli, L., Rigotti, A., Greco, A. V., Santos, M. J., and Nervi, F. (1995) J. Biol. Chem. 270, 18723-18726) [4].
• Like SCP2, recombinant SCPx also stimulates the microsomal conversion of 7-dehydrocholesterol to cholesterol and transfers phosphatidylcholine and 7-dehydrocholesterol from small unilamellar vesicles to acceptor membranes in vitro [13].

Associations of Scp2 with chemical compounds

• Each of the genes Scp2, Sqle and Fdft1 maps close to a QTL for serum total cholesterol in rat, suggesting that these three genes might represent candidate genes for the previously mapped QTLs [14].
• Rats (Day 3 pregnant) received an injection of streptozotocin (STZ, 60 mg/kg; i.v.) to induce a diabetic state; P450scc, 3 beta-HSD, and SCP2 were examined by Western and Northern blot analysis in ovarian tissue 12 days after injection of STZ (diabetic rats, n = 12) or vehicle (nondiabetic rats, n = 12) [10].
• Increased SCPx expression coincided with increased serum triglyceride and beta-HBA levels, suggesting that the enhanced SCPx level may coincide with an ovarian shift to fatty acid metabolism [10].
• The C-terminal sequence of SCPx is identical to SCP2, while its N-terminal region is homologous with 3-oxoacyl coenzyme A thiolase, an enzyme involved in fatty acid metabolism [10].
• The amino acid sequence of Sterol Carrier Protein2 (SCP2) isolated from rat has been investigated [15].

Physical interactions of Scp2

• Characterization of a steroidogenic factor-1-binding site found in promoter of sterol carrier protein-2 gene [16].

Other interactions of Scp2

• These results are concordant with the possibility that reduced steroid levels in the diabetic animals reflect a loss of SCP2-mediated cholesterol transport capacity as SCPx/3-oxoacyl coenzyme A thiolase expression is enhanced [10].
• We investigated the effects of 8 days of LH withdrawal on rat Leydig cell peroxisomal volume, total and intraperoxisomal catalase and sterol carrier protein-2 (SCP2) contents, and LH-stimulated testosterone secretion in vitro [17].

Analytical, diagnostic and therapeutic context of Scp2

• Restriction mapping and nucleotide sequencing analyses of these cDNAs indicate that eight extend upstream of the SCP2 cDNA, and two extend 5' as well as 3'. Translation of the sequence extending most upstream suggests that this cDNA is a nearly full-length cDNA coding for a protein of 547 amino acids (SCP chi) [6].
• Consistent with the loss of SCP2 mRNA expression, Western blot analysis indicated that a 15-kilodalton SCP2-immunoreactive protein (presumably the pro-SCP2 form) was significantly reduced or absent in the PGF2 alpha treated animals (P < 0.04).(ABSTRACT TRUNCATED AT 400 WORDS)[9]
• The production of cholic acid and chenodeoxycholic acid from the precursors on incubation with the bifunctional protein and sterol carrier protein x or P-44 was confirmed by gas chromatography [18].
• The occurrence and subcellular distribution of the non-specific lipid transfer protein (nsL-TP; sterol carrier protein 2) in rat tissues was investigated by the immunoblotting technique using the affinity purified antibody against rat liver nsL-TP [19].
• By gel chromatography, enzyme immunoassay and immunoblotting it was demonstrated that the activity in the wash was due to the nonspecific lipid transfer protein (sterol carrier protein 2) [20].

References