* I HE distribution of phosphatases during the embryonic development of X Drosophila melanogaster Meig. was chosen as the next object of study for three main reasons: (i) a satisfactory technique for the demonstration of phosphatase (at least in the case of alkaline phosphatase) is available-, (2) the possible significance of phosphatases during embryogenesis is indicated by the work of Moog (1...

1. The characteristics of Ca2+-activated ATPase activities previously often postulated as components for the calcium transporting system in fish gills do not fulfil the requirements of a transport Ca: '-ATPase. 2. The chelation of Ca;~or Mg:~-ions is a prerequisite for the adenosinephosphate esters to serve as substrate for gill plasma membrane phosphatases. 3. Ca2+-activated ATP hydrolysis res...

What to do on a hot summer afternoon? Sneak over and dip into the neighbor’s pool! This seems to be the story for the newest inhibitors of the Cdc25 phosphatases. Brisson et al. (2004), in this issue, present one of the most promising reversible competitive Cdc25 inhibitors to date, blocking cell cycle progression and causing growth arrest of cancer cell lines. Before considering the benefits o...

The phosphatidylinositol 3-kinase (PI3K) pathway plays a pivotal role in the maintenance of processes such as cell growth, proliferation, survival, and metabolism in all cells and tissues. Dysregulation of the PI3K/Akt signaling pathway occurs in patients with many cancers and other disorders. This aberrant activation of PI3K/Akt pathway is primarily caused by loss of function of all negative c...

Nonspecific acid phosphatases are a group of enzymes whose activity increases the availability of exogenous and endogenous orthophosphate either through extra- or intracellular hydrolysis of phosphate compounds. Our study demonstrates the activity of acid phosphatases in the filamentous freshwater alga Stigeoclonium tenue. These enzymes were detected following a cerium-based method in which cer...

RNA polymerase II carboxyl-terminal domain (pol II CTD) phosphatases are a newly emerging family of phosphatases that are members of DXDX (T/V). The subfamily includes Small CTD phosphatases, like SCP1, SCP2, SCP3, TIMM50, HSPC129 and UBLCP. Extensive study of SCP1 has elicited the diversified roles of the small C terminal domain phosphatase. The SCP1 plays a vital role in various biological ac...

Phosphorylation and dephosphorylation of cellular proteins by protein kinases and phosphatases represent important mechanisms for controlling major biological events. In the nervous system, protein phosphatases are contained in highly dynamic complexes localized within specialized subcellular compartments and they ensure timely dephosphorylation of multiple neuronal phosphoproteins. This modula...

There are over 100 genes in the human genome that encode protein tyrosine phosphatases (PTPs) and approximately 60 of these are classified as dual-specificity phosphatases (DUSPs). Although many dual-specificity phosphatases are still not well characterized, novel functions have been discovered for some of them that have led to new insights into a variety of biological processes and the molecul...