Disease relevance of Pura

• Furthermore, overexpression of ovine Pur alpha enhanced transactivation of the oPL gene proximal promoter in both choriocarcinoma cell lines through this novel cis-element [1].
• Pur alpha binding to linear duplex DNA creates binding sites for the phage T4 gp32 protein, an ss-DNA binding protein that does not itself bind linearized DNA [2].

Psychiatry related information on Pura

• Involvement of a single-stranded DNA binding protein, ssCRE-BP/Pur alpha, in morphine dependence [3].

High impact information on Pura

• Moreover, transient expression of Pur alpha caused elevation in the level of endogenous MBP RNA in oligodendrocytic cells [4].
• The HeLa cDNA library also includes a clone encoding a related gene, Pur beta, containing a version of the 23-amino-acid consensus motif similar, but not identical, to those in Pur alpha [5].
• Conversely, gain-of-function studies indicated that Pur alpha or Pur beta could each independently repress core smooth muscle alpha-actin enhancer activity albeit in a cell type-dependent fashion [6].
• These findings support the hypothesis that Pur alpha and Pur beta repress smooth muscle alpha-actin gene transcription by means of DNA strand-selective cis-element binding and cell type-dependent protein-protein interactions [6].
• However, Pur alpha and Pur beta exhibited more distinctive protein interaction profiles when evaluated for binding to enhancer-associated transcription factors in extracts from fibroblasts and vascular smooth muscle cells [6].

Biological context of Pura

• The data suggest a novel gene expression pathway mediated by Ca/CaM-Pur alpha which may regulate a variety of genes in addition to those regulated through the CREB pathway [7].
• Biochemical analyses indicated that purified recombinant Pur alpha and Pur beta were essentially identical in terms of their binding affinity and specificity for GGN repeat-containing strands of several cis-elements comprising the core enhancer [6].
• Pur alpha and Pur beta are structurally related single-stranded DNA/RNA-binding proteins implicated in the control of cell growth and differentiation [6].
• GADD45g, a gene responsible for regulating cell cycle arrest and apoptosis, was significantly induced; as was Pura, a gene involved in cell proliferation [8].
• Thus, Pur alpha, a sequence-specific DNA-binding protein upon binding to MB1 regulatory region may play a significant role in determining the cell type-specific expression of MBP in brain [4].

Anatomical context of Pura

• These data suggest that rat lung and the eosinophils contain a 45-kDa ssCRE-BP/Pur alpha that is increased when airway inflammation occurs [9].
• Immunohistochemistry showed that ssCRE-BP/Pur alpha is primarily distributed in the lung epithelium [9].
• Pur alpha protein implicated in dendritic RNA transport interacts with ribosomes in neuronal cytoplasm [10].

Associations of Pura with chemical compounds

• Calmodulin functions as an activator of Pur alpha binding to single-stranded purine-rich DNA elements (PUR elements) [7].
• Mutational analysis indicates that arginine and aromatic residues in the repeat region of Pur alpha are essential for both ss- and duplex DNA binding [2].
• Pur alpha is a single-stranded (ss) DNA- and RNA-binding protein with three conserved signature repeats that have a specific affinity for guanosine-rich motifs [2].
• This series is likely due to localized unwinding by quanta of Pur alpha since removal of Pur alpha in the gel eliminates the series and since Pur alpha binding increases the sensitivity of plasmids to reaction with potassium permanganate, a reaction specific for unwound regions [2].
• We have previously demonstrated that chronic morphine treatment decreases the DNA binding activity of ssCRE-BP (single-stranded cyclic AMP response element-binding protein), which has been shown to be identical to pur alpha by cDNA cloning, and is abundant in the brain [11].

Physical interactions of Pura

• Nucleoprotein interactions governing cell type-dependent repression of the mouse smooth muscle alpha-actin promoter by single-stranded DNA-binding proteins Pur alpha and Pur beta [6].
• These biochemical properties of the PurBPs are different from the reported nuclear Pur alpha-binding proteins such as Sp1 and pRb [12].

Other interactions of Pura

• The goal of this study was to determine whether Pur alpha and Pur beta function in a redundant, distinct, or collaborative manner to suppress smooth muscle alpha-actin gene expression in cell types relevant to wound repair and vascular remodeling [6].
• Additional experiments indicated that Pur alpha, Pur beta, and MSY1 also interact specifically, albeit weakly, with double-stranded DNA and with transcription enhancer factor-1 [13].
• In studies of mice, we previously identified two homologous single-stranded (ss)(CAG) and ss(CGG) repeat-binding proteins, CAGER-1 (44 kDa) and CAGER-2 (40 kDa) (CAG-element-recognizing proteins) [14].
• Our previous studies have shown that the binding activity of a nuclear factor (ssCRE-BP) to single-stranded CRE of somatostatin gene is altered by long-term treatment with morphine in the mouse cerebellum. ssCRE-BP was purified from the mouse cerebellum by a combination of chromatography on DNA affinity agarose and Mono Q HR [15].
• We found a ssCRE-BP/Pur alpha (45 kDa) in rat lung that was larger than those (40 kDa) identified in rat and mouse brains and mouse lung [9].

Analytical, diagnostic and therapeutic context of Pura

• Cell cycle arrest and morphological alterations following microinjection of NIH3T3 cells with Pur alpha [16].
• Cells injected with Pur alpha during S or G2 phases were efficiently blocked with a 4N (G2 phase) DNA level, as determined by quantitative DNA photometry of individual cells [16].

References