TL;DR: A 3-dimensional model for a DNA−protein interaction has been developed that provides a footing for the observation that the cooperation of all four CBF3 components is absolutely required to constitute an activity that specifically interacts with centromere DNA.
Abstract: A 3-dimensional model for a DNA-protein interaction has been developed. The protein component is the 61-residue fragment (res. 11-71) of subunit b of the yeast centromeric DNA binding factor 3, CBF3b. The CBF3b fragments bind to the 17 base pairs (5'-CGGAGGACTGTCCTCCG-3') as a symmetric homodimer, with each folded into three distinct conformations: a compact, zinc-binding domain (res. 11-44); an extended linker (res. 45-57); and an alpha-helical dimerization element (res. 58-71). The DNA fragment in the complex is featured by a relatively straight conformation with only slight deviation from a standard B-structure, and a large part of the major groove not blocked by the protein. The large DNA open area provides the necessary space for the other subunits of CBF3 to bind coordinately with CBF3b, fully consistent with the observation that the cooperation of all four CBF3 components is absolutely required to constitute an activity that specifically interacts with centromere DNA. The model also provides a footing for further considering the possible binding arrangements of the other three subunits, namely CBF3a, CBF3c, and CBF3d.
TL;DR: R reverse transcription-quantitative polymerase chain reaction and the databases of The Cancer Genome Atlas, Oncomine, Gene Expression Profiling Interactive Analysis and the Multi Experiment Matrix were combined to assess the expression of HOXA1 and its co-expressed genes in NSCLC and showed that HOxA1 was upregulated in NS CLC.
Abstract: Homeobox A1 (HOXA1) serves an oncogenic role in multiple cancer types. However, the role of HOXA1 in non‑small cell lung cancer (NSCLC) remains unclear. In the present study, use of reverse transcription-quantitative polymerase chain reaction and the databases of The Cancer Genome Atlas (TCGA), Oncomine, Gene Expression Profiling Interactive Analysis and the Multi Experiment Matrix were combined to assess the expression of HOXA1 and its co-expressed genes in NSCLC. Bioinformatic analyses, such as Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and network and protein-protein interaction analyses, were used to investigate the underlying molecular mechanism effected by the co-expressed genes. Additionally, the potential miRNAs targeting HOXA1 were investigated. The results showed that HOXA1 was upregulated in NSCLC. The area under the curve of HOXA1 indicated a moderate diagnostic value of the HOXA1 level in NSCLC. According to GO and KEGG analyses, the co-expressed genes may be involved in 'dGTP metabolic processes', 'network-forming collagen trimers', 'centromeric DNA binding' and 'the p53 signaling pathway'. Three miRNAs (miR‑181b‑5p, miR‑28‑5p and miR‑181d‑5p) targeting HOXA1 were each predicted by 10 algorithms; miR‑181b and miR‑181d levels were downregulated in LUSC tissues compared with those in normal lung tissues based on data from the TCGA database, and inverse correlations were found between HOXA1 and miR‑181b (r=-0.205, P<0.001) and miR‑181d (r=-0.106, P=0.020). We speculate that HOXA1 may be the direct target of miR‑181b‑5p or miR‑181d‑5p in LUSC, and HOXA1 may serve a significant role in NSCLC by regulating various pathways, particularly the p53 signaling pathway. However, the detailed mechanism should be verified by functional experiments.
TL;DR: The phylogenetic history of this protein and of its DNA binding site shows independent events of function acquisition across different species and raises questions on the evolutionary dynamics of CENP-B, including what may be the selective advantage provided by its role at the centromere.