Regulation of Gene
Expression by SAR of Silkworm Attacus ricini rRNA Gene
WU Zhen-Yu, ZHAO Mu-Jun*, LI Zai-Ping
( Shanghai Institute of Biochemistry, the Chinese Academy of Sciences；the Open Lab of Molecular Cell
Biology, the Chinese Academy of Sciences, Shanghai 200031, China )
Abstract The 1 kb
scaffold attachment region (SAR) at 5′ non-transcription region of rRNA gene of
silkworm Attacus ricini was cloned into eukaryotic expression vector pLu,
which contained luciferase report gene and neo R selecting
marker. After transfection of constructs into NIH3T3 cell line by using cation
liposome, the luciferase activity was monitored to check the SAR’s function.
The results demonstrated that the SAR could enhance gene expression up to
15-fold in stable transformed cells, but no obvious gene expression was
observed in transient transfection. Its effect on gene expression appeared to
requirechromosomal integration. Southwestern blotting experiments showed that
SAR specifically bound to nuclear matrix proteins of NIH3T3 cells. The binding
with nuclear matrix may be necessary for SAR function of transcriptional
enhancement.
Key words silkworm Attacus ricini；rRNA gene；SAR；luciferase gene；Southwestern blotting
*Corresponding author：Tel,86-21-64374430-295；Fax,86-21-64338357；e-mail,[email protected]