The translation initiation factor eIF2beta is an interactor of protein phosphatase-1.

It is reasonably well understood how the initiation of translation is controlled by reversible phosphorylation of the eukaryotic translation initiation factors eIF2alpha, eIF2Bepsilon and eIF4E. Other initiation factors, including eIF2beta, are also established phosphoproteins but the physiological impact of their phosphorylation is not known. Using a sequence homology search we found that the central region of eIF2beta contains a putative PP1-(protein phosphatase-1) binding RVxF-motif.

Proteolytic maturation and activation of autotaxin (NPP2), a secreted metastasis-enhancing lysophospholipase D.

Autotaxin (NPP2) is an extracellular protein that is upregulated in various malignancies, including breast and lung cancer. It potently stimulates cell proliferation, cell motility and angiogenesis, which is accounted for by its intrinsic lysophospholipase-D activity that generates the lipid mediators lysophosphatidic acid and sphingosine-1-phosphate. Based on its structural similarities with the better characterized nucleotide pyrophosphatase/phosphodiesterase NPP1, it has always been assumed that NPP2 is also synthesized as a type-II integral membrane protein and that extracellular NPP2 is generated from this membrane precursor.

The nuclear scaffold protein NIPP1 is essential for early embryonic development and cell proliferation.

NIPP1 (nuclear inhibitor of protein phosphatase 1) is a ubiquitously expressed nuclear scaffold protein that has been implicated in both transcription and RNA processing. Among its protein ligands are a protein kinase, a protein phosphatase, two splicing factors, and a transcriptional regulator, and the binding of these proteins to NIPP1 is tightly regulated by phosphorylation. To study the function of NIPP1 in vivo, we have used homologous recombination to generate mice that are deficient in NIPP1.