As miRNA concentration is a function of biogenesis and turnover, active miRNA degradation might also regulate miRNA accumulation.
The ECM turnover and remodeling are extremely active in the tumor microenvironment [ 111].
They focused on the incorporation of the histone variant H3.3, which is a hallmark of sites of high nucleosome turnover, and is associated with active genes and their regulatory elements [ 5, 6].
Turnover of active (microbial biomass and labile substrates), slow (chemically protected), and passive (physically protected) fractions of the SOM are represented.
Turnover numbers based on the standard assay and active site titrations are listed in Table 1.
Either of these outcomes would predict that a population of neurons requiring higher levels of active actin turnover and having high ATP demands would be greatly affected in HD.
This observation is consistent with the fact that neucleoli have active protein turnover and also with our previous report that C D labeled newly synthesized proteins are more prominent in nucleoli.
Maintenance of mitochondrial oxidative metabolism and energy production is particularly relevant at nerve endings, where mitochondria are essential to maintain protein turnover and exo-endocytotic processes at active synapses (Li et al, 2004).
These results further support our conclusion that high H3.3 turnover marks active interactions between DNA and protein factors.
Enzyme function involves substrate and cofactor binding, precise positioning of reactants in the active site, chemical turnover, and release of products.
Among the keratinocyte-specific genes showed in Figure 6C, we found various keratins, transcription factors, and proteolytic enzymes (and their inhibitors) that are active in protein turnover and remodeling in keratinocytes, and which are not common to other cell types [37].
