Regulating the Expression of Protein Phosphatase Type 5

Publisher Summary This chapter is based on regulating the expression of protein phosphatase type 5. Serine/threonine phosphatase 5 (PP5) is an okadaic acid, microcystin, calyculin A sensitive phosphatase that is highly conserved among species and expressed ubiquitously in mammalian tissues. The chapter presents the reasons for difficulty in determining the physiological/ pathological roles of PP5. Although studying changes in PP5 activity is difficult, the expression of PP5 in mammalian cells can be suppressed by treatment with antisense oligonucleotides or small double stranded molecules of RNA. Antisense oligonucleotides are synthetic, small DNA molecules, designed to bind in a Watson-Crick fashion to a target mRNA. The chapter describes the double-stranded RNA interference (dsRNAi) method. For both techniques, target specificity is derived from the precise sequence of the target mRNA. Thus, unless the sequence of the target mRNA is identical, the oligonucleotides are species specific. Unfortunately, there is no completely reliable way to predict a region in the target mRNA that will serve as a suitable target, so for both techniques screening is still required to identify effective oligonucleotides in other species.