protein tyrosine phosphatases (ptpases) regulate tyrosine phosphorylation of target proteins involved in several aspects of cellular functions. enzyme activities of the ptpases in cytosolic and particulate fractions of rat ascites hepatoma cell lines were determined and compared with those of normal rat liver. our present data revealed that although there was no neoplatic-specific alteration of...

Cell cycle deregulation and genomic instability play a major role in the aberrant cell proliferation that characterizes tumorigenesis. A novel role of the cyclin e isoform cyclin e2 in these processes is reported in the manuscript " Cyclin e2 induces genomic instability by mechanisms distinct from cyclin e1 " by Caldon et al. 1 in another issue of Cell Cycle, evidence that regulation of cyclin ...

Protein phosphorylation has long been known to play a key role in triggering the synaptic changes underlying learning and memory. Recent studies highlight the importance of tightly regulated dephosphorylation as a mechanism controlling the induction of long-term synaptic change and lasting memory.