Dual specificity phosphatases of the Cdc25 family are critically important regulators of the cell cycle. They activate cyclin-dependent kinases (CDKs) at key cell cycle transitions such as the initiation of DNA synthesis and mitosis. They also represent key points of regulation for pathways monitoring DNA integrity, DNA replication, growth factor signaling and extracellular stress. Since their ...

INTRODUCTION Diagnosis of adrenal disease in domestic animals usually is dependent on the manipulation of the hypothalamo-pituitary-adrenal axis (HPA) and the measurement of cortisol (i.e., ACTH stim test; low dose dexamethasone suppression (LDDS) test; urine cortisol/creatinine ratio test; or the combined dexamethasone suppression/ACTH stimulation test). More recently, other steroid measuremen...

© 2008 Weller et al. The Rockefeller University Press $30.00 J. Exp. Med. Vol. 205 No. 6 1331-1342 www.jem.org/cgi/doi/10.1084/jem.20071555 1331 In humans, peripheral blood B cells expressing the CD27 marker and mutated Ig receptors are usually considered to be memory B cells generated in germinal centers (GCs) during immune responses to T-dependent (TD) antigens. In adults, approximately half ...

Neoplasia is characterised by abnormal regulation of the cell cycle. Cyclin D1 is a protein derived from the PRAD1, CCND1 or bcl-1 gene on chromosome 11q13, which is involved in both normal regulation of the cell cycle and neoplasia. In the G1 (resting) phase of the cell cycle, cyclin D1 together with its cyclin dependent kinase (cdk) partner, is responsible for transition to the S (DNA synthes...

Knowledge about adhesion checkpoints is important to counteract dissemination of cells from solid tumors. Lack of anchorage in adherent cells is associated with growth arrest and inhibition of cyclin-dependent kinases (cdks) required to drive cell cycle progression. Because cyclin-cdk complex activation requires CDK-activating kinase comprising cdk7 and cyclin H, we now investigated their relat...

The two major processes common to all cell cycles are S phase, when chromosomes are replicated, and M phase, when the replicated chromosomes are segregated into two daughter cells. In most cell cycles, an interval of time, G1 phase, separates the previous cell division from the beginning of the next S phase. It is now firmly established that progression of the cell cycle – that is, transitions ...

Tumor cells have a dysregulated cell cycle that may render their proliferation especially sensitive to the inhibition of cyclin-dependent kinases (CDKs), important regulators of cell cycle progression. We examined the effects of CDK1 inhibition in the context of different oncogenic signals. Cells transformed with MYC, but not cells transformed by a panel of other activated oncogenes, rapidly un...

Using the conditionally immortalized human cell line tsFHI, we have investigated the role of cyclin-dependent kinase inhibitors (CKIs) in intestinal epithelial cell differentiation. Expression of cyclins, cyclin-dependent kinases (Cdk), and CKIs was examined under conditions promoting growth, growth arrest, or expression of differentiated traits. Formation of complexes among cell cycle regulato...

Background and novelty Mammalian cells growth, productivity and cell death are highly regulated and coordinated processes. The cell cycle is at the centre of cellular control and should play a key role in determining optimization strategies towards improving productivity [1]. Specifically, cell productivity is cell cycle, cell-line and promoter dependant [2]. The cyclins are key regulators that...

The activity of cyclin dependent kinases (CDKs), which are key regulators of the eukaryotic cell cycle, is regulated through post-translational mechanisms, including binding of a cyclin and phosphorylation. Previously studies have shown that Leishmania mexicana CRK3 is an essential CDK that is a functional homologue of human CDK1. In this study, recombinant histidine tagged L. mexicana CRK3 and...