Disease relevance of Tbl1xr1

• The purpose of this study was to determine whether porins (outer membrane proteins) of Salmonella typhimurium G30/C21 would influence the activity of macrophages from lipid A-responsive and -unresponsive mice [1].
• Characterization of a series of mouse monoclonal antibodies (designated alpha Py C21 to 26) against the region common to the large, middle and small T antigens of polyoma virus has revealed immunological diversities among the N termini of these antigens [2].

High impact information on Tbl1xr1

• The checkpoint function of NCoR is relieved by signal-dependent phosphorylation of c-Jun, which directs removal of NCoR/HDAC3/TBL1/TBLR1 complexes through recruitment of a specific ubiquitylation complex, as a prerequisite to the default binding of c-Jun/c-Fos heterodimers and transcriptional activation [3].
• Specific de novo methylation of C21-derived sequences does not occur in L cells or Y1 kin8 cells; this suggests that the cellular factors needed for de novo methylation of the C21 gene are not ubiquitous [4].
• DNA fragments encoding the mouse steroid 21-hydroxylase (C21 or Cyp21A1) gene are de novo methylated when introduced into the mouse adrenocortical tumor cell line Y1 by DNA-mediated gene transfer [4].
• Most DNA sequences are not de novo methylated when introduced into somatic cells and DNA sequences other than the C21 gene are not de novo methylated when introduced into Y1 cells [4].
• Although CCGG sequences within the C21 gene are de novo methylated, CCGG sites within flanking vector sequences, other mammalian gene sequences driven by the C21 promoter, and the neomycin-resistance gene, which was cotransfected with the C21 gene, do not become methylated [4].

Biological context of Tbl1xr1

• At least two separate signals for de novo methylation are encoded within the gene since three fragments derived from the C21 gene were methylated de novo [4].
• A 9-kilobase BglII fragment containing the C21 gene was cloned from the Y1 genome [5].
• The capacity for C21 steroid biosynthesis in primitive gut and skin during organogenesis raises the question whether local production of steroid hormones may be required for normal cellular growth and differentiation of these tissues during embryogenesis [6].
• Then, established transfectant cells C21 and C34 expressed definite levels of GM1, and analyzed for the cell growth with the control cells D2 and D4 expressing no GM1 [7].
• Since Leydig cell P production is dramatically increased during high-dose stimulation with LH/hCG, due to blockade of C21 steroid side chain cleavage, the present findings offer a function for this steroid in the LHR down-regulation [8].

Anatomical context of Tbl1xr1

• In this investigation the mechanisms underlying the loss of C21 activity in the Y1 cell line were explored [5].
• In immature mouse testes, the results indicate two biosynthetic pathways leading to C19 steroids from progesterone, one from progesterone via 17-hydroxyprogesterone and androstenedione to testosterone and a second via 5alpha-reduced C21 steroids to 5alpha-reduced C19 steroids such as androsterone and 5alpha-androstane-3alpha,17beta-diol [9].
• It was also biosynthesized from GM1b and CMP-NeuNAc by NIE and chick embryo cells but not by C21 cells, or rat brain [10].

Associations of Tbl1xr1 with chemical compounds

• This genomic clone directed the synthesis of C21 transcripts and 21-hydroxylated steroid products when transfected back into the Y1 cell line [5].
• Furthermore, treatment of Y1 cells with 5-azacytidine caused a demethylation of the endogenous C21 gene, but did not result in the recovery of C21 expression [5].
• Here, we report on the identification of such an analog, which was synthetically derived from ascomycin (ASC), the C21 ethyl analog of tacrolimus, by introducing an indole group at the C32 position [11].
• The new analogue, containing an additional hydroxyl group at C21, exhibits advantages over other epothilones in terms of water solubility, and can serve as a readily functionalizable handle to produce other useful compounds for pertinent biological studies [12].
• The resultant 17 alpha-hydroxylated, C21 pregnene is converted to a C19 androgen by the C17,20-lyase activity [13].

References