Cell function processes

The classification of these dmgs as antimetaboHtes stems from the mode of action as antagonists to the natural metaboHc processes leading to either DNA, RNA, or proteiu synthesis (13) (see Nucleic acids Proteins). They either inhibit function of a key en2yme involved in protein synthesis or are recmited into the cell division process as DNA synthesis terrninators. For example, methotrexate (8) is a foHc acid [59-30-3], antagonist and... 

Originally described in the immune system, NFAT proteins comprise a family of transcriptional factors that play key roles in many cellular processes that control not only immune responses but also the development, regulation, and differentiation of many other tissues. Activation of NFAT proteins results in the expression of specific sets of genes that regulate multiple cell functions [1,2]. 

The process by which cells take up large molecules is called endocytosis. Some of these molecules (eg, polysaccharides, proteins, and polynucleotides), when hydrolyzed inside the cell, yield nutrients. Endocytosis provides a mechanism for regulating the content of certain membrane components, hormone receptors being a case in point. Endocytosis can be used to learn more about how cells function. DNA from one cell type can be used to transfect a different cell and alter the latter s function or phenotype. A specific gene is often employed in these experiments, and this provides a unique way to smdy and analyze the regulation of that gene. DNA transfection depends upon endocytosis endocy-... 

Cerklewski and Forbes 1976). Also, excess zinc protects zinc-containing enzymes like ALAS, ferrochelatase, and ALAD. In vivo, aqueous solution containing zinc administered to rats significantly reduced the genotoxic effects induced by lead (Kowalska-Wochna et al. 1988). It was postulated that zinc s protective action may be related to its functioning in DNA and RNA polymerases and consequent enhancement of cell repair processes. 

The number of channels synthesized, processed, and trafficked to the apical membrane and rate of CFTR internalization at the apical membrane determine the cell surface density. Mutations in CFTR that alter one or more of these parameters decrease total CFTR-mediated anion flux and impair epithelial cell function. 

We assembled a TIRFM with low magnification to study cell adhesion behavior on SAMs with various functional groups [42]. Figure lb shows a schematic illustration of the cell adhesion process and the corresponding TIRFM images. A suspension of cells with fluorescently labeled cell membranes is applied onto a substrate (Fig. lb-1). At first, no bright spots were observed by TIRFM,... 

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