Delivery of imaging agents to brain glioma is challenging because the blood brain barrier (BBB) functions as a physiological checkpoint guarding the central nervous system from circulating large molecules.
This provides further evidence that the stage 7/8 egg chamber apoptosis and corresponding oviposition decrease is a specific physiological checkpoint, similar to that previously described for poor nutritional intake (Drummond-Barbosa and Spradling, 2001).
This, together with the observation that alternative splicing is abrogated by the presence of the checkpoint kinase inhibitor caffeine, indicates that alternative splicing of HBP/SLBP is a physiological, checkpoint-mediated response that may contribute to the down-regulation of histone gene expression observed under replication stress conditions.
The important physiological consequence of checkpoint signaling is a mitotic delay.
Nevertheless, failure to degrade cyclin B at anaphase onset in mouse zygotes causes mitotic checkpoint-dependent inhibition of APC/CCdc20 substrate degradation [ 24], suggesting physiological importance of mitotic checkpoint dissolution by Cdk1 inactivation.
Physiological activation of the AMPK metabolic checkpoint in response to nutrient depletion and energy stress suppresses energy-consuming cellular processes such as protein synthesis and cell division.
Therefore, it is interesting to know whether Rho serve as a checkpoint for both the physiological environment and the availability of chemical GPCR ligands to decide on cell proliferation and differentiation.
Here, we review the interplay between the nuclear envelope, chromatin and DNA damage checkpoint pathways, and discuss the physiological and pathological implications of these associations.
NHEJ, HR and checkpoint proteins all play roles in physiological telomere maintenance.
Furthermore, a direct interaction between Rad14 and the 9-1-1 checkpoint complex was reported, albeit its physiological significance has not been fully addressed.
