Role of the 14-3-3 proteins in the regulation of H+-ATPase activity in the plasma membrane of suspension-cultured sugar beet cells under cold stress.

All higher plants possess highly specific binding sites for fusicoccin, a metabolite of the fungus Fusicoccum amygdali Del. These sites are harboured in the plasma membranes and formed by a 14-3-3 protein dimer associated with the C-terminal autoinhibitory domain of H+-ATPase. We considered the fusicoccin binding to plasma membranes to be an indicator of complexation between the 14-3-3 dimer and H+-ATPase, we assessed the effect of cold stress on the interaction of these proteins in suspension-cultured sugar beet cells and protoplasts derived from these cells.

Organization of fusicoccin receptor in higher plant plasma membrane: relationship between affinity and molecular mass.

Higher plant plasma membranes carry receptors of different affinity for the phytotoxin fusicoccin. Reception of fusicoccin involves proteins belonging to the highly conserved 14-3-3 family, but the complete structure of the fusicoccin receptor (FCR) is unknown. Using radiation inactivation analysis, we estimated the molecular masses of low-affinity and high-affinity FCR at 63 +/- 7 and 130 +/- 15 kD, respectively.

Nucleotide G-1207 of 18S rRNA is an essential component of the human 80S ribosomal decoding center.

mRNA analogues-derivatives of oligoribonucleotides consisting of two different codons and bearing an aryl azide group at the 5'-phosphates-were crosslinked to human 80S ribosomes by UV-irradiation of the various model complexes obtained in the presence of the cognate tRNAs. Three sequences, namely pUUUGUU (coding for Phe and Val), pUUCUAAA (first triplet coding for Phe and second being stop-codon), and pGUGUUU (coding for Val and Phe), have been used. Sequences of 18S rRNA containing nucleotides crosslinked to the mRNA analogues were examined by hydrolysis with RNase H in the presence of various cDNA probes.

Plant cell pH-static circuit mediated by fusicoccin-binding proteins.

On sugar beet protoplasts that carry two types of fusicoccin-binding sites, a pH downshift in a physiological range (7.0-6.6) markedly enhanced the efficiency of fusicoccin (FC) binding, mainly owing to increased avidity of low-affinity FC-binding sites.

Liver plasma membrane-associated fibroblast growth: stimulatory and inhibitory activities during experimental cirrhosis.

During experimental CCl4 cirrhosis, an increase of membrane-associated factor stimulating 3T3 cell proliferation in vitro was observed. This stimulator is a 150-kD protein similar to one previously described. In situ perfusion released growth stimulatory activity, suggesting a peripheral plasma membrane protein localizing on basolateral surfaces.