Disease relevance of DDEF1

• Confirming the microarray findings, DDEF1 mRNA levels and protein expression were significantly higher in high-grade melanomas [1].
• Expression of AMAP1, an ArfGAP, provides novel targets to inhibit breast cancer invasive activities [2].
• This AMAP1-mediated trimeric protein complex was detected only in invasive cancer cells, and blocking this complex formation effectively inhibited their invasive activities in vitro and metastasis in mice [2].
• Pulmonary alveolar proteinosis (PAP) is a heterogeneous disorder of genetic or acquired etiologies [3].
• Here, we describe an expression defect of beta c in three of seven pediatric patients with PAP and in one patient with severe lung disease suspected to be PAP [3].

Psychiatry related information on DDEF1

• Increased serum pancreatitis associated protein (PAP) concentration after longterm alcohol consumption: further evidence for regular subclinical pancreatic damage after heavy drinking [4]?
• Through discussion of ASAP, an alcohol and substance abuse prevention program for youth from high-risk communities in New Mexico, this article presents an interweaving of Freirian theory and protection-motivation cognitive change theory [5].

High impact information on DDEF1

• Among the paxillin-binding ArfGAPs, AMAP1 has recently been strongly implicated in tumor invasion as well as malignancy, owing to its highly augmented expression in tumors and its direct involvement in invasive activities [6].
• This study showed that B43-PAP can effectively eradicate leukemic progenitor cells freshly obtained from patients with common B-lineage ALL [7].
• Human melanoma cells were selected for resistance to in vitro killing of the PAP conjugate by cycling through a killing and recovery sequence [8].
• A novel platelet-agglutinating protein (PAP) was purified approximately 2,000-fold from the plasma of a patient with thrombotic thrombocytopenic purpura (TTP) by ammonium sulfate fractionation, DEAE-Sephacel and concanavalin A-Sepharose chromatographies [9].
• Using this antiserum in the Western immunoblotting, the 37,000-mol wt protein band was found in the three TTP plasmas, of which the platelet-agglutinating activity was inhibited by the anti-37,000-mol wt PAP IgG [9].

Chemical compound and disease context of DDEF1

• Targeting AMAP1 and cortactin binding bearing an atypical src homology 3/proline interface for prevention of breast cancer invasion and metastasis [10].
• To examine if KL-6, a mucinlike glycoprotein, is useful for the diagnosis of PAP and the estimation of its activity, serum KL-6 levels in patients with PAP were measured by an enzyme-linked immunosorbent assay and compared with those of patients with other lung diseases [11].
• Phase II evaluation of the AMAP, 773U82 mesylate, in pancreatic cancer [12].
• At a concentration of 5 microM, recombinant PAP released 263 +/- 10 pmol of adenine and 100 +/- 11 pmol of guanine from 1 microgram of E. coli ribosomal RNA (16S + 23S) within 4 h of treatment [13].
• Recombinant PAP released adenine and guanine residues at a 1:1 ratio from HIV-1 RNA and at an approximately 3:1 (adenine:guanine) ratio from Escherichia coli ribosomal RNA [13].

Biological context of DDEF1

• RESULTS: In melanomas analyzed for microarray gene expression and CGH, gain of chromosome 8q correlated most strongly with expression of DDEF1, a gene located at 8q24 [1].
• DDEF1 is located in an amplified region of chromosome 8q and is overexpressed in uveal melanoma [1].
• Furthermore, ectopic expression of DDEF1 in low-grade melanoma cells resulted in a significant increase in cell motility, a feature of high-grade metastasizing cells [1].
• We conclude that DDEF1 may act as an oncogene in this cancer, and it may be a useful diagnostic marker and therapeutic target [1].
• We found that GAP activity requires the cognate PH domain of ASAP1, leading us to hypothesize that the Arf GAP and PH domains directly interact to form the substrate binding site [14].

Anatomical context of DDEF1

• Here we found that an ArfGAP, AMAP1/PAG2, is expressed at high levels in highly invasive breast cancer cells, but at very low levels in noninvasive breast cancer cells and normal mammary epithelial cells. siRNA-mediated silencing of AMAP1 effectively blocked the invasive activities [2].
• CrkL directs ASAP1 to peripheral focal adhesions [15].
• Similar to ASAP1, ACAP1 and ACAP2 were recruited to and, when overexpressed, inhibited the formation of platelet-derived growth factor (PDGF)-induced dorsal membrane ruffles in NIH 3T3 fibroblasts [16].
• SMAP2, a novel ARF GTPase-activating protein, interacts with clathrin and clathrin assembly protein and functions on the AP-1-positive early endosome/trans-Golgi network [17].
• GITs also participate in receptor internalization by regulating membrane trafficking between the plasma membrane and endosomes, targeting ARF GTPases through their ARF GTPase-activating protein (ARF-GAP) activity [18].

Associations of DDEF1 with chemical compounds

• The results of saturation kinetics, limited proteolysis, FRET and fluorescence spectrometry support a model in which regulation of the GAP activity of ASAP1 involves a conformational change coincident with recruitment to a membrane surface, and a second conformational change following the specific binding of phosphatidylinositol 4,5-bisphosphate [14].
• Centaurin beta4 proteins are products of the DDEF1 (development and differentiation-enhancing factor 1) locus on human chromosome 8q24.1-24 [19].
• The largest differences were observed with a change of isoleucine 46 to aspartate ([I46D]Arf1), which reduced ASAP1-induced catalysis by approximately 10,000-fold but had a 3-fold effect on AGAP1 [20].
• Human prostatic acid phosphatase (hPAP, EC.3.1.3.2), a secretory homodimeric protein was denatured in 6 M urea, pH 2.5, and refolded by dilution at pH 7.2 with recovery of the enzymatic activity and dimeric structure [21].
• By directly interacting with both Arfs and tyrosine kinases involved in regulating cell growth and cytoskeletal organization, ASAP1 could coordinate membrane remodeling events with these processes [22].

Physical interactions of DDEF1

• POB1 formed a complex with PAG2 in intact cells [23].
• AlFx affects the formation of focal complexes by stabilizing the Arf-GAP ASAP1 in a complex with Arf1 [24].
• Together with fine structural analysis, we propose that the AMAP1/cortactin complex, which is not detected in normal mammary epithelial cells, is an excellent drug target for cancer therapeutics [10].
• Further characterization of CIN85 binding to ASAP1 revealed that formation of the complex is independent on cell stimulation [25].

Co-localisations of DDEF1

• We found that CIN85 colocalizes with AMAP1 at invadopodia, and binding of AMAP1 with CIN85 is important for the invasive activities of breast cancer cells, including MDA-MB-231. siRNA-mediated silencing of CIN85, as well as Cbl, also inhibited the invasion [26].

Other interactions of DDEF1

• Furthermore, a heterozygous SNP in DDEF1, a putative candidate gene, suggested that MKS3 mapped within a 15-cM interval [27].
• We found that AMAP1 is also localized at invadopodia, and acts to bridge paxillin and cortactin [2].
• Substitutions of Pro(423) and Pro(426) with Ala (POB1(PA)) impaired the binding of POB1 to PAG2 [23].
• Searching for proteins in platelets that can interact with the N-terminal SH3 domain of CrkL (using a combination of a pull-down assay followed by mass spectrometry), we have found that human platelets express an ADP-ribosylation factor (Arf)-specific GTPase-activating protein (GAP), ASAP1, as a CrkL-binding protein [15].
• These results suggest that POB1 interacts with PAG2 through its proline-rich motif, thereby regulating cell migration [23].

Analytical, diagnostic and therapeutic context of DDEF1

• Using affinity chromatography and mass spectrometry (MS), we identified the adaptor protein CD2-associated protein (CD2AP) as a candidate binding partner of ASAP1 [28].
• We measured thermodilution cardiac output, mean PA pressure (MPAP), PA pulse pressure (PAPP = systolic - diastolic PAP) and normalized PAPP (nPAPP = PPAP/MPAP) [29].
• Acute elevations in PAP/SAP accompanied by clinical deterioration occurred during attempted withdrawal from cardiopulmonary bypass in three patients, during apparently optimal ventilation postoperatively in eight patients, and after withdrawal of ventilatory support in four patients [30].
• In mice, the PAP phenotype was generated by targeted deletion of the gene for betac and can be treated by transplantation of wild-type bone marrow into betac -/- mice [31].
• Through site-directed mutagenesis, we provide evidence that PAP contains a functional ribonucleoprotein-type RNA binding domain (RBD) that is responsible for primer binding, making it the only known polymerase to contain such a domain [32].

References