Regulation of transcription of rRNA synthesis by Apak under hypoxic conditions / 军事医学

ABSTRACT

Objective To explore the effect and mechanism of Kruppel-associated box(KRAB) type zinc-finger protein Apak on the transcription of ribosomal RNA(rRNA) under hypoxic conditions.Methods Real-time quantitative PCR(qRT-PCR) was used to detect the level of rRNA and the effect of Apak on the transcription of rRNA.The expression and phosphorylation level of proteins were examined by Western blotting.Immunofluorescence assay was used to observe the location of Apak.Results Under hypoxia (0.3%O2),the transcription level of rRNA increased first and then decreased in Apak wild type cells.In Apak knock-out cells,the transcription level of rRNA kept decreasing under hypoxic conditions.The repression of Apak on rRNA synthesis and the nucleolus location of Apak disappeared,and the expression and phosphorylation level of Apak were down-regulated under hypoxic conditions for 3 h.Conclusion Under hypoxic conditions,the disapperance of Apak repression on rRNA transcription could lead to a temporary increase in rRNA.