Disease relevance of Dffb

• A caspase-activated deoxyribonuclease (CAD) and its inhibitor (ICAD) have now been identified in the cytoplasmic fraction of mouse lymphoma cells [1].
• Role of Apoptotic Nuclease Caspase-Activated DNase in Etoposide-Induced Treatment-Related Acute Myelogenous Leukemia [2].
• During the characterization of the staurosporine-induced apoptotic process in human neuroblastoma cell lines, we have found three novel splice variants of CAD [3].
• Thus, GnRH-DFF40 is a promising candidate for the treatment of adenocarcinomas in humans [4].
• CONCLUSIONS: Because GnRH-DFF40 is a whole human-based chimeric protein when applied to humans, the nonspecific toxicity and immunogenicity seen with bacterial/plant-based chimeric proteins should be avoided [4].

High impact information on Dffb

• We show here that Cidea, a protein of unknown function sharing sequence similarity with the N-terminal region of DNA fragmentation factors Dffb and Dffa, is expressed at high levels in BAT [5].
• A caspase-activated DNase that degrades DNA during apoptosis, and its inhibitor ICAD [1].
• CAD (caspase-activated DNase) can cause DNA fragmentation in apoptotic cells [6].
• Transgenic mice that ubiquitously express a caspase-resistant form of the CAD inhibitor (ICAD) were generated [6].
• Caspase-activated DNase (CAD) is an endonuclease that is activated in dying cells, whereas DNase II is present in the lysosomes of macrophages [7].

Chemical compound and disease context of Dffb

• Posttranscriptional regulation of the expression of CAD gene during differentiation of F9 teratocarcinoma cells by induction with retinoic acid and dibutyryl cyclic AMP [8].
• Immunisation of BALB/c mice with a vaccine containing Vi polysaccharide conjugated to the Klebsiella pneumoniae outer membrane 40kDa protein (rP40), in combination with Escherichia coli heat-labile toxin adjuvant (LT), elicited anti-Vi IgG antibodies after administration using different routes [9].
• Mechanism of inhibition of ascites tumor growth in mice by curcumin is mediated by NF-kB and caspase activated DNase [10].

Biological context of Dffb

• Here, we describe the assignment of murine CAD and ICAD genes to the distal part of murine chromosome 4 [11].
• Analyses of the promoter activity with a series of deletion mutants of their 5' flanking regions indicated that a 190-bp 5' flanking region of the CAD gene was sufficient to promote the transcription [11].
• Molecular cloning and structural analysis indicated that CAD and ICAD genes are comprised of 7 and 6 exons, respectively [11].
• There is sequence homology of about 80 amino acid residues at the N termini of CAD and ICAD (called the CAD domain) [12].
• Enzymatic active site of caspase-activated DNase (CAD) and its inhibition by inhibitor of CAD [13].

Anatomical context of Dffb

• CAD was predominantly associated with ICAD-L in these cell lines [14].
• In contrast, reticulocyte lysates stimulated ICAD-L- and ATP-dependent renaturation of denatured CAD without requiring a high concentration of reducing agents [15].
• We also provided evidence showing that UVA induces caspase-3 and caspase-activated DNase (CAD) activity in both H2AX wild-type and H2AX knockout mouse embryonic fibroblasts (MEFs) [16].
• We showed that CAD and ICAD are co-localized in microsome, nuclei and cytosol in unstimulated thymocytes [17].
• These results demonstrate that TCR engagement of thymocytes induces caspase-3-dependent activation of CAD localized in both cytosol and microsome, leading to DNA fragmentation in harmony [17].

Associations of Dffb with chemical compounds

• Analysis by site-directed mutagenesis suggested that at least four histidine residues in the C-terminal part of the molecule are essential for the catalytic activity of CAD DNase [13].
• Here, we established a quantitative assay for CAD DNase that measures the number of 3' hydroxyl groups on the CAD-generated DNA fragments [13].
• Saturation transfer experiments were performed for the (2)H- and (15)N-labeled mouse CAD domain of the caspase-activated deoxyribonuclease and the CAD domain of its inhibitor to reveal the protein-protein complexed conformation [18].
• Involvement of conserved histidine, lysine and tyrosine residues in the mechanism of DNA cleavage by the caspase-3 activated DNase CAD [19].
• Chemical modification of murine CAD with the lysine-specific reagent 2,4,6-trinitrobenzenesulphonic acid and the tyrosine-specific reagent N-acetylimidazole leads to inactivation of the nuclease, indicating that lysine and tyrosine residues are important for DNA cleavage by this enzyme [19].

Physical interactions of Dffb

• In proliferating cells, CAD is complexed with ICAD (inhibitor of CAD) and its DNase activity is suppressed [13].

Regulatory relationships of Dffb

• Following in vivo TCR engagement, ICAD located in cytosol and microsome was degraded and the resulting activated CAD induced chromosomal DNA fragmentation [17].
• CAD present in cytosol and microsome of unstimulated thymocytes was activated by recombinant caspase-3, and microsomal CAD was released to the cytosol [17].

Other interactions of Dffb

• On the basis of structural comparison with other protein complexes containing the ubiquitin superfold, the interaction mode of the CAD domains is proposed [12].
• This molecular mechanism for the inhibition of CAD DNase by ICAD is similar to that proposed for colicin endonuclease and its inhibitor, immunity protein [13].
• These findings suggest that CIIA is an endogenous antagonist of both ASK1- and CAD-mediated signaling [20].
• In one, the DNA fragmentation is carried out by CAD in the dying cells and in the other, by lysosomal DNase II after the dying cells are phagocytosed [21].
• Caspases were activated, and the death substrates of caspases, lamin B and ICAD (an inhibitor of caspase-activated DNase), were cleaved in this cell death process [22].

Analytical, diagnostic and therapeutic context of Dffb

• Here, we report the three-dimensional structure of the CAD domain of CAD determined by multi-dimensional NMR spectroscopy and the property of CAD domains investigated by a surface plasmon resonance experiment [12].
• ICAD in extracts of wild type Jurkat cells also existed at approximately 440 and 45 K as measured by gel chromatography; so that fractions of CAD coincided with fractions of approximately 440 K of ICAD [23].
• Southern blot analysis of colonies that survived normally cytotoxic concentrations of PALA exhibited CAD gene amplification [24].
• Finally, endogenous NT3 was detectable in CAD cell extracts by a specific ELISA assay [25].
• Biosynthetic radiolabel incorporation studies in concert with urea-sodium dodecylsulfate-polyacrylamide gel electrophoresis (urea-SDS-PAGE) and western immunoblotting revealed that two major proteins of approximately 26 and 40kDa were produced by the construct [26].

References