For nearly 150 years, it has been recognized that cell shape strongly influences the orientation of the mitotic cleavage plane (e.g., Hofmeister, 1863). However, we still understand little about the complex interplay between cell shape and cleavage-plane orientation in epithelia, where polygonal cell geometries emerge from multiple factors, including cell packing, cell growth, and cell division...

Cell entry by paramyxoviruses requires fusion of the viral envelope with the target cell membrane. Fusion is mediated by the viral fusion (F) glycoprotein and usually requires the aid of the attachment glycoprotein (G, H or HN, depending on the virus). Human respiratory syncytial virus F protein (F(RSV)) is able to mediate membrane fusion in the absence of the attachment G protein and is unique...

Abstract A key hallmark of Alzheimer’s disease is the extracellular deposition amyloid plaques composed primarily amyloidogenic amyloid-β (Aβ) peptide. The Aβ peptide a product sequential cleavage Amyloid Precursor Protein, first step which gives rise to C-terminal Fragment (C99). Cleavage C99 by γ-secretase activity releases several lengths and Aβ42 isoform in particular has been identified as...

introduction: pronuclear size, morphology and orientation are known to affect embryo quality and implantation. the present study was aimed at evaluation of the possible relationship between protamine deficiency with pronuclear morphology and also cleavage and embryo quality. material and methods: semen sample of 160 candidate icsi and ivf couples were analyzed for sperm concentration, and motil...

Many phytopathogenic bacteria use a type III secretion system to deliver type III effector proteins into the host plant cell. The Pseudomonas syringae type III effector AvrRpt2 is cleaved at a specific site when translocated into the host cell. In this study, we first demonstrate that the factor(s) required for AvrRpt2 cleavage is present in extracts from animal and yeast cells, as well as plan...

The precursor protein p62 of the prototype alphavirus Semliki Forest virus (SFV) undergoes during transport to the cell surface a proteolytic cleavage to form the mature envelope glycoprotein E2. To investigate the biological significance of this cleavage event, single amino acid substitutions were introduced at the cleavages site through mutagenesis of cDNA corresponding to the structural regi...

In this study the programmed cell death (apoptosis) of human neutrophilic granulocytes was investigated in the presence and absence of fetal calf serum (FCS), cycloheximide and actinomycin-D. The results show that when FCS is omitted from cultures, apart from a decrease in viability, the percentage of apoptotic cells and DNA fragmentation increases. Apoptosis is accelerated in serum withdra...