Disease relevance of MYBBP1A

• P185 BCR-ABL produced in a cell line derived from a Ph chromosome-positive acute lymphocytic leukemia patient also co-immunoprecipitated with P160 BCR [1].

High impact information on MYBBP1A

• In contrast to the v-abl oncogene product P160, the P210 bcr/abl gene product did not transform NIH/3T3 cells [2].
• Tyrosine phosphorylation of P160 BCR by P210 BCR-ABL [3].
• Induction of PAP-2a mRNA was not affected by the protein synthesis inhibitor cycloheximide and was accompanied by a marked increase in PAP-2 activity as measured by the conversion of phosphatidic acid into diacylglycerol in membrane fractions of LNCaP [4].
• When an octyl glucoside extract of surface-radioiodinated platelets was applied to an affinity matrix of KYGRGDS-coupled Sepharose 4B, a 160-kDa-labeled protein (P160) and GPIIb-IIIa bound and were specifically eluted by soluble GRGDSP peptide, but not by the variant GRGESP peptide [5].
• Importantly, the phosphotyrosine content of total P160 BCR (induced plus endogenous) was strongly reduced by inducing expression of Bcr, indicating that the induced Bcr protein was not a target of the tyrosine kinase activity of Bcr-Abl but instead functioned as an inhibitor of Bcr-Abl [6].

Biological context of MYBBP1A

• A novel, polymorphic (CA)(25) dinucleotide repeat was also isolated from this PAC and may serve as a useful marker for MYBBP1A and this region of chromosome 17 [7].
• Given the likely presence of a tumor suppressor gene (or genes) within this region of chromosome 17, the position of MYBBP1A was further mapped by radiation hybrid analysis and was found to lie between markers D17S1828 and D17S938 [7].
• A P1 artificial chromosome clone containing the 5' region of MYBBP1A was isolated and indicates a physical linkage between MYBBP1A and the 15-lipoxygenase gene (ALOX15) [7].
• Molecular cloning and chromosomal mapping of the human homologue of MYB binding protein (P160) 1A (MYBBP1A) to 17p13.3 [7].
• MYBBP1a was found to compete with the histone acetyl transferase co-activator, p300, for interaction with the transcription activation domain of RelA/p65 [8].

Anatomical context of MYBBP1A

• P210 BCR-ABL is complexed to P160 BCR and ph-P53 proteins in K562 cells [9].
• Expression levels of MYBBP1a are dependent on the cell type, and are particularly high in Jurkat T cells [8].

Analytical, diagnostic and therapeutic context of MYBBP1A

• We now describe the molecular cloning of the human MYBBP1A cDNA and chromosomal localization to 17p13.3 by fluorescence in situ hybridization analysis [7].
• Moreover, direct association of P160 with a beta subunit having an apparent molecular weight similar to that of GPIIIa was demonstrated by immunoprecipitation with LM609, an anti-VnR complex monoclonal antibody [5].

References