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Retroviral integration has recently been shown to be nonrandom, favoring transcriptionally active regions of chromatin. However, the mechanism for integration site selection by retroviruses is not clear. We show here the occurrence of Alu-like motifs in the sequences flanking the reported viral integration sites that are significantly different from those obtained from the randomly picked sequences from the human genome, suggesting that unique primary sequence features exist in the genomic regions targeted by human immunodeficiency virus type 1 (HIV-1). Additionally, these sequences were preferentially bound by SATB1, the T lineage-restricted chromatin organizer, in vitro and in vivo. Alu repeats make up nearly 10% of the human genome and have been implicated in the regulation of transcription. To specifically isolate sequences flanking the viral integration sites and also harboring both Alu-like repeats and SATB1-binding sites, we combined chromatin immunoprecipitation with sequential PCRs. The cloned sequences flanking HIV-1 integration sites were specifically immunoprecipitated and amplified from the pool of anti-SATB1-immunoprecipitated genomic DNA fragments isolated from HIV-1 NL4.3-infected Jurkat T-cell chromatin. Moreover, many of these sequences were preferentially partitioned in the DNA associated tightly with the nuclear matrix and not in the chromatin loops. Strikingly, many of these regions were disfavored for integration when SATB1 was silenced, providing unequivocal evidence for its role in HIV-1 integration site selection. We propose that definitive sequence features such as the Alu-like motifs and SATB1-binding sites provide a unique chromatin context in vivo which is preferentially targeted by the HIV-1 integration machinery.

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Synthesis of C-11 azido/amino functionalized cholic acid derivatives has been achieved in excellent yields. Contrary to the previous prediction of analogous compounds to be HIV-1 protease inhibitors, in the present study these novel cholic acid derivatives induced host cell fusion during the progress of HIV-1 infection and produced multinucleated giant cells. This is the first report of syncytia induction and enhancement of viral replication in HIV-1 infected T cells by cholic acid derivatives.

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The Insilco analysis of SERK (Somatic Embryogenesis Receptor Kinase) gene which helps in the ovulation time of plantation crops [14,15] with thus evidence, the current study was preceded in Cocos nucifera. The SERK gene was retrieved from NCBI and appropriate protein sequence alignment for this protein sequence was done, for finding the evolutionary relationship of the SERK in Cocos nucifera and other plantation crops. A phylogenetic tree was constructed and it was found that there is more similarity for Cocos nucifera towards Arabidopsis thaliana. Primers were designed based on conserved regions of SERK genes reported from other plant species and then they were amplificated by using PCR technique. Homology modeling was done for the CnSERK, Where leucine rich repeats and serine/threonine regions was found, this gives more information regarding the function of SERK protein.