Disease relevance of PABPC4

• Activated platelet-derived growth factor autocrine pathway drives the transformed phenotype of a human glioblastoma cell line [1].
• Activated platelet aggregates in thrombotic thromboctyopenic purpura: decrease with plasma infusions and normalization in remission [2].
• A detailed analysis of its amino acid sequence confirmed that the protein is an aminopeptidase P-like enzyme with greater similarity to Escherichia coli APP than to either APP1 or APP2 [3].

Psychiatry related information on PABPC4

• To better understand the role the human amyloid precursor protein (hAPP) plays in Alzheimer's disease (AD), it is essential to define its primary function(s) [4].

High impact information on PABPC4

• iPABP, an inducible poly(A)-binding protein detected in activated human T cells [5].
• In contrast, PABP is constitutively expressed in both resting and activated T cells. iPABP mRNA was also expressed at much higher levels than PABP mRNA in heart and skeletal muscle tissue [5].
• Next, using the luciferase reporter assay in both C. neoformans wild-type and GAL7:IPC1 strains, we investigated the role of DAG and sphingolipids in the activation of the APP1 promoter and found that treatment with 1,2-dioctanoylglycerol does increase APP1 transcription, whereas treatment with phytosphingosine or ceramides does not [6].
• Two putative consensus sequences were found in the APP1 promoter for ATF and AP-2 transcription factors [6].
• Mutagenesis analysis of these sequences revealed that they play a key role in the regulation of APP1 transcription: ATF is an activator, whereas AP-2 in a negative regulator [6].

Chemical compound and disease context of PABPC4

• The tyrosine kinase Fyn is altered in Alzheimer's disease brains and modulates premature mortality and synaptotoxicity in hAPP mice [7].

Biological context of PABPC4

• The iPABP gene has been assigned to chromosome 1 [8].
• The pseudogenes PABP4, 1, and 2 have been assigned to chromosomes 15, 4, and 14, respectively [8].
• Here, we identified two types of cDNA clones coding for poly(A)-binding protein (PABP) and inducible PABP (iPABP) by screening an expression cDNA library with the GST-Tob probe [9].
• Consistently, over-expression of Tob in NIH3T3 cells, in which exogenous iPABP was stably expressed, resulted in suppression of IL-2 production from the simultaneously transfected IL-2 expression plasmid [9].
• The full-length cDNA coding for human APP-1, obtained by DNA hybridization techniques, showed 98.7% amino acid sequence identity with the rabbit protein [10].

Anatomical context of PABPC4

• A 2.3-kb cDNA fragment containing a partial coding sequence for APP-1 was isolated from a rabbit bone marrow library by expression cloning with the anti-APP-1 monoclonal antibody [10].
• By virtue of its ribonucleotide binding domains, APP-1 is structurally related to polyadenylate-binding protein, which regulates translation initiation and polyadenylate shortening, and to nucleolysin, a specific effector molecule found in the granules of cytotoxic T lymphocytes [10].
• Human amyloid precursor protein (hAPP) transgenic mice with high levels of amyloid-beta (Abeta) develop behavioral deficits that correlate with the depletion of synaptic activity-related proteins in the dentate gyrus [7].

Other interactions of PABPC4

• PABPC5 has 73% nucleotide identity with PABPC4 over 1801 bp of the ORF [11].
• Interaction of anti-proliferative protein Tob with poly(A)-binding protein and inducible poly(A)-binding protein: implication of Tob in translational control [9].
• Semi-quantitative RT-PCR analysis suggested that up-regulation of IL-6 expression and down-regulation of PDGFR, APP-1 and KGF-1 expressions in multiple cell lines assayed, were compatible with the results of the microarray analysis [12].

Analytical, diagnostic and therapeutic context of PABPC4

• Co-immunoprecipitation and GST-pull down experiments showed that Tob associated with the carboxyl-terminal region of iPABP [9].

References