ABSTRACT
Objective To analyze the human cellular repressor of E1A-stimulated genes (hCREG)using bioinformatics tools and predict the promoter position and transciption factor binding sites.Methods Complete coding hCREG sequences were obtained from Genbank.hCREG was analyzed with First EF software in order to obtain the promoter sequence of hCREG.Moreover,transcription factor binding sites of hCREG was convinced by Motif software.Subsequently,the transcription factor of hCREG by bioinformatics tools was related between hCREG and smooth muscle cells differentiation observed by both Western blot and immunoflourescence.Results The promoter of hCREG was located in -109~-359 bp of up-stream of transcriptional site,which was predicted with 945bp length.Transciption factor binding sites of hCREG was predicted by Motif software which was found with 80 transciption factors.The expression of hCREG and smooth muscle ?-actin(SM ?-actin)increased in HITASY after 72 hours with serum deprivation detected by both Western blot and immunoflourescence.Meanwhile,the results showed that the expression of wtp53 increased significantly.These results suggested that transcription factor wtp53 might regulate the expression of hCREG and promoted dedifferentiated phenotype of VSMCs.Conclusion The transcriptional information of the proximal promoter of hCREG obtained.As up-stream regulational factor of hCREG,wtp53 can up-regulate the expression of hCREG and may play a vital role in the process of VSMCs differentiation and phenotype modulation.
ABSTRACT
The interaction of the oligopeptides Ala-Gln-GIn-Leu-Ala-Gly-OH and Gln-Leu- Ala-Gly-OMe corresponding, respectively, to the sequence 53–58 and 55–58 of lac repressor protein with four polynucleotides was studied. The two peptides did not interact with poly dA. poly dT, poly d(A-T).poly d(A-T) or poly d(A-G).poly d(C-T). But they interacted in a characteristic way with poly d(A-C). poly d (G-T), the sequences of which are in abundance in the lac operator region. Both the peptides stabilised the melting of poly d (A-C). poly d (G-T) at a peptide to nucleotide ratio (P/N) of 4; at lower ratios, they destabilised the DNA slightly. The circular dichroism of the alternating polynucleotide with CAC/GTG sequences was perturbed by both the oligopeptides. The hexapeptide at a P/N of 4 caused the transformation of the Bform circular dichroism spectrum to a new state, characterised by strong 220 and 240 nm bands, and a rather weak long wavelength spectrum.