Fumonisins are inhibitors of the biosynthesis of sphingosine and more complex sphingolipids. In eucaryotic cells, fumonisin inhibition of sphingolipid biosynthesis is a result of inhibition of the enzyme ceramide synthase. Large increase in free sphinganine concentration in plant and animal cells are observed within a few hours after exposure to fumonisins and/or Alternaria toxins (AAL-toxins)....

Low molecular weight intracellular sulfhydryl-containing compounds are responsible for the intracellular detoxification of metals such as Cd and Cu in eucaryotic phytoplankton. Glutathione, the most abundant thiol in non-stressed cells (0.8 to 2.8 mM), chelates metals directly, and also serves as the biochemical precursor from which phytochelatins are synthesized. Very little is known about phy...

Rhino- and enteroviruses encode two proteinases, 2A and 3C, which are responsible for the processing of the viral polyprotein and for cleavage of several cellular proteins. To identify further targets of the 2A proteinase of human rhinovirus serotype 2 (HRV2), an in vitro cleavage assay followed by two-dimensional electrophoresis was employed. Cytokeratin 8, a member of the intermediate filamen...

In a previous study (Y. Kimura et al., Biosci. Biotechnol. Biochem., 70, 2583-2587, 2006), we found that new complex type N-glycans harboring Thomsen-Friedenreich antigen (Galbeta1-3GalNAc) unit occur on royal jelly glycoproteins, suggesting the involvement of a new beta1-3galactosyltransferase in the synthesis of the unusual complex type N-glycans. So far, such beta1-3galactosyltransferase act...

A fundamental problem of cellular biology is to understand the mechanisms underlying cellular locomotion. Bacterial organisms may use appendages such as flagellae or cilia to facilitate motion. Amoeboid motion [6], exhibited by eucaryotic cells are seen to flatten onto surfaces and extend thin sheets of cytosol called lamellipodia. These in turn make attachments to the surface and by the initia...

Because of the high degree of organizational complexity of eucaryotic cells, it is clear that the implementation of their genetic programs must, in many cases, involve a complex sequence of cotranslational and posttranslational events that are necessary to transfer polypeptides from their sites of synthesis to their sites of function. It is difficult to envisage the existence of a single genera...