Immunocytochemical characterization of clathrin-associated proteins (CAPs)

Cell and Tissue Research - Clathrin-associated proteins (CAPs) elicited antibodies in rabbits that were affinity-purified using CAPs-conjugated CNBr-Sepharose 4B. Anti-CAPs IgG formed...     

Vesicle formation from the nuclear envelope in amphibian oocytes

Conclusions Electron microscopic evidence has been presented which suggests that the cytoplasmic vesicles observed in amphibian oocytes are derived by blebbing from the nuclear envelope and migrate to the periphery. The mechanism of bleb formation is discussed.This work was supported by a U.S.P.H.S. research grant RG5803(C2) and was carried out during the tenure of a U.S.P.H.S. Special Research Fellowship (5356).     

Glycogen phosphorylase is involved in stress endurance and biofilm formation in Azospirillum brasilense Sp7

Here we report the identification of a glycogen phosphorylase ( glgP ) gene in the plant growth-promoting rhizobacterium Azospirillum brasilense , Sp7, and the characterization of a glgP marker exchange mutant of this strain. The glgP mutant showed a twofold reduction of glycogen phosphorylase activity and an increased glycogen accumulation as compared with wild-type Sp7, indicating that the identified gene indeed encodes a protein with glycogen phosphorylase activity. Interestingly, the glgP mutant had higher survival rates than the wild type after exposure to starvation, desiccation and osmotic pressure. The mutant was shown to be compromised in its biofilm formation ability. Analysis of the exopolysaccharide sugar composition of the glgP mutant revealed a decrease in the amount of glucose, accompanied by increases in rhamnose, fucose and ribose, as compared with the Sp7 exopolysaccharide. To the best of our knowledge, this is the first study that demonstrates GlgP activity in A. brasilense , and shows that glycogen accumulation may play an important role in the stress endurance of this bacterium.     

Cold tolerance of Pseudomonas sp. 30-3 isolated from oil-contaminated soil, Antarctica

Pseudomonas sp. 30-3 was enriched from oil-contaminated soil from Wright Valley, Antarctica using JP8 jet fuel as sole carbon source. This isolate exhibited tolerance to temperatures ranging from 0°C to 35°C when cultured in laboratory medium. In a freeze-thaw study, an 89% survival was observed when Pseudomonas sp. 30-3 was exposed to 4°C prior to freezing. PCR amplification of a 248-bp DNA fragment in Pseudomonas sp. 30-3 using capB-gene specific primers showed a 98% amino acid sequence homology with CapB of Pseudomonas fragi and 62% homology with CspA of Escherichia coli. Radiolabeling of total cellular proteins exhibited elevated expression of an 8-kDa protein at 4°C, which suggests that the CapB in Pseudomonas sp. 30-3 may play a pivotal role in survival and tolerance at cold and subzero temperatures. Tolerance to cold temperatures and the ability to degrade hydrocarbons by Pseudomonas sp. 30-3 provide support for the application of bioremediation for petroleum hydrocarbons in Antarctic soils.