High impact information on Pp1-13C

• Together these data suggest that PP1c is targeted to Dpp receptor complexes by Sara, where it acts as a negative regulator of Dpp signaling by affecting the phosphorylation state of the type I receptor [1].
• KLP38B was isolated through its two-hybrid interaction with the catalytic subunit of type 1 serine/threonine phosphoprotein phosphatase (PP1) [2].
• In contrast, expression of transgenes encoding the Bif F995A mutant, which disrupts binding to PP1, was unable to rescue any aspect of the bif phenotype [3].
• The gene bifocal (bif), required for photoreceptor morphogenesis in the Drosophila compound eye, encodes a protein that is shown to interact with protein phosphatase 1 (PP1) using the yeast two-hybrid system [3].
• Type 1 serine/threonine protein phosphatases (PP1) are important regulators of many cellular and developmental processes, including glycogen metabolism, muscle contraction, and the cell cycle [1] [2] [3] [4] [5] [4].

Biological context of Pp1-13C

• Phosphatase inhibitor-2 (I-2) is a mammalian phosphoprotein that binds to the catalytic subunit of type 1 serine/threonine phosphoprotein phosphatase (PP1c) and inhibits its activity in vitro [5].
• Drosophila is an excellent model organism in which to characterize the role of PP1 catalytic and regulatory subunits, because it combines molecular and biochemical approaches with powerful genetics, in a well-characterized animal model [6].
• Regulatory subunits of PP1 provide the key to understanding the role of PP1, as they are responsible for directing PP1c to different intracellular locations and/or affecting their activity or substrate specificity [6].
• These results suggest that scapinin is a putative regulatory subunit of PP1 and is involved in transformed or immature phenotypes of HL-60 cells [7].
• We have isolated human cDNA for a novel type 1 protein phosphatase (PP1) inhibitory protein, named inhibitor-4 (I-4), from a cDNA library of germ cell tumors [8].

Anatomical context of Pp1-13C

• Protein phosphatase type 1 (PP1) is one of the major classes of serine/threonine protein phosphatases and has been found in all eukaryotic cells examined to date [6].
• Bifocal and PP1 interaction regulates targeting of the R-cell growth cone in Drosophila [9].

Associations of Pp1-13C with chemical compounds

• Recombinant PP1c differs from native PP1c in several biochemical criteria, including the requirement for Mn(2+), sensitivity to vanadate, and p-nitrophenyl phosphate (pNPP) phosphatase activity [5].
• PP1 (protein phosphatase-1), a major class of serine/threonine protein phosphatase, is found at many sites on Drosophila polytene chromosomes where it is involved in controlling gene expression and chromatin structure [10].

Analytical, diagnostic and therapeutic context of Pp1-13C

• A yeast two-hybrid assay revealed that this protein bound to the catalytic subunit of protein phosphatase-1 (PP1) [7].
• Interaction between PP1c and TRX was confirmed in vivo by co-immunoprecipitation from Drosophila extracts [11].

References