DSIF Pure 17/DSIF 50ug

In living systems, the relative amounts of any protein are controlled at many levels. For example, amounts are affected by protein degradation,

regulation of the translational rates of polypeptide synthesis (translational regulation), and control of the rates of mRNA synthesis

(transcriptional regulation). Transcriptional regulation involves modulation of the rate-limiting enzyme RNA polymerase. DSIF (DRB

sensitivity-inducing factor) is a heterodimeric transcription elongation protein. It is composed of a large subunit of 160 kDa and a small

subunit of 14 kDa. These large and the small subunits are homologs of the yeast gene products Stp5 and Stp4, respectively. Spt4 and 5 are

transcription factors which are critically important for the activity of RNA polymerase. In conjunction with DRB, DSIF attenuates RNA

polymerase II elongation steps. However, in limiting amounts of ribonucleotides, DSIF, by itself, stimulates the elongation rate of RNA

polymerase II. Thus, the identification of a human regulator for transcriptional elongation will greatly enhance our understanding of this

critical step in mammalian gene expression.

1.Since applications vary, each investigator should titrate the reagent to obtain optimal results.

2.Caution: Sodium azide yields highly toxic hydrazoic acid under acidic conditions. Dilute azide compounds in running water before discarding to avoid accumulation of potentially explosive deposits in plumbing.