In fact, other types of programmed cell death have recently been reported based not only on the cell morphology but also on the proteins involved in the signaling cascade. A programmed necrosis dubbed paraptosis has thus been reported (Asare et al., 2008, Bursch et al., 2000 and Sperandio et al., 2004). Paraptosis is characterized by cytoplasmic Cetuximab vacuolization and lack of apoptotic morphology such as plasma membrane blebbing and nuclear fragmentation. Recently a candidate mediator of paraptosis, prohibitin, was reported

(Sperandio et al., 2010). The plasma membrane is the first barrier or cellular protection encountered by xenobiotics, and plasma membrane perturbation is often considered as an early event in chemical-induced cell death; it may thus represent an important feature in classification of the different modes of cell deaths. It has also become clear that it represents an important event involved in cell fate following cytotoxic insults. The dynamic properties of the plasma Trichostatin A chemical structure membrane play a central role in cell signaling involved in various cell survival, differentiation and death pathways. There are also specific membrane changes related to endocytosis, cell division, as well as separation of cell from tissues during

cancer metastasis (Patra, 2008). Transmembrane proteins such as receptors, signaling molecules, various ion channels and transporters are transducing extracellular signals inside the cells, thereby triggering specific

intracellular pathways. Recently it has become clear that changes in membrane microstructure may strongly regulate/modulate the activity or efficiency of membrane proteins and affect cellular homeostasis. Lipid/membrane rafts are specialized Cell Cycle inhibitor small (10–200 nm), heterogeneous domains within the plasma membrane.They are highly dynamic and form sterol- and sphingolipid-enriched domains that compartmentalize various cellular processes (Fig. 1). Caveolae are a subclass of such rafts, characterized by flask-like invaginations of the plasma membrane and the presence of caveolin-1 (cav-1). Due to their unique content of lipids, lipid rafts serve as specialized membrane areas for molecular assemblages of proteins and gangliosides. They are known for their pivotal role in macromolecule internalization, sorting of sphingolipids and cholesterol in the cell, and as platforms to concentrate receptors and assembling the signal transduction machinery. However, their ability to influence the actin cytoskeleton, cell polarity, angiogenesis and membrane fusion is probably just as significant (Staubach and Hanisch, 2011). The existence of two subsets of lipid-related rafts in cell membrane has been suggested.