ABSTRACT
Over the past decade, our understanding of apoptosis, or programmed cell death, has increased greatly, with the identification of some of the major components of the apoptotic programme and the processes regulating their activation. Although apoptosis is an intrinsic process present in all cells, it can be regulated by extrinsic factors, including hormones, growth factors, cell surface receptors, and cellular stress. The actions of both pro- and antiapoptotic factors are often affected by modulation of the phosphorylation status of key elements of the apoptotic process. This minireview will focus on the role of protein kinases in apoptosis. Apoptosis is a multistep process and protein kinases have been implicated both in the upstream induction phase of apoptosis and in the downstream execution stage, as the direct targets for caspases. Due to the space constraints of this review it is not possible to discuss all of the kinases involved in the apoptotic process and we have focused here on the role of the serine/threonine protein kinases. The kinases of this family that have been suggested to play a role in apoptosis are the mitogen-activated protein kinase (MAPK) family, specifically p42/44 ERK, p38 MAPK and c-Jun N-terminal kinase (JNK), cyclic AMP-dependent protein kinase (PKA), protein kinase B (PKB), or Akt and protein kinase C (PKC). We have also considered briefly the potential for the regulation of these kinases by tyrosine protein kinases, such as c-abl.
Subject(s)
Apoptosis/physiology , Protein Serine-Threonine Kinases/metabolism , Animals , Cyclic AMP-Dependent Protein Kinases/metabolism , Humans , JNK Mitogen-Activated Protein Kinases , Mitogen-Activated Protein Kinases/metabolism , Models, Biological , Protein Kinase C/metabolism , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-akt , Signal TransductionABSTRACT
This study investigated maternal speech to age-matched and linguistically matched deaf and hearing 2-yr-old and 5-yr-old infants. Maternal speech features that were examined included complexity, selected utterance, and sentence types, repetitions, expansions, utterance acceptability, and fluency. Results revealed more significant differences in maternal speech to age-matched hearing and deaf children than to linguistically matched child groups. In addition, child deafness itself seemed to account for other characteristics of maternal speech, and their possible effects on the communicative development of the deaf child were discussed.
