In an effort to understand how polarity is established in Xenopus oocytes, we have analyzed the process of localization of the maternal mRNA, Vg1. In fully grown oocytes, Vg1 mRNA is tightly localized at the vegetal cortex. Biochemical fractionation shows that the mRNA is preferentially associated with a detergent-insoluble subcellular fraction. The use of cytoskeletal inhibitors suggests that ...

Treatment of either Mycobacterium tuberculosis or M. smegmatis with ethambutol results both in inhibition of arabinan synthesis and in copious loss of previously formed arabinan from the cell wall. The loss of arabinan has been shown to be due to the action of an endogenous arabinase. To better understand this phenomenon, a quantitative assay for endogenous arabinase was developed. Using the as...

, TETANUS toxin is fixed by the grey matter of nervous tissue (WASSERMA. .:N and TAKcAIKI, 1898; FULTHORPE, 1956; VAN HEYNINGEN, 1959a). JANOFF (1964) has recently reported evidence of selective fixation of the toxin by subcellular fractions of rabbit brain homogenate spun down between 800 g x 10 min and 17,000 & x 20 min (mitochondria and lysosomes) and between 17,000 g x 10 nin and 100,000 g ...

The roles of subcellular distribution on silver (Ag) accumulation and elimination in the green mussel Perna viridis collected from 2 hydrographical zones (harbour vs. estuarine) in Hong Kong during 3 different seasons were investigated. Ag concentration and biokinetics varied widely between the 2 zones, but were less variable among the different seasons (pre-wet, wet and dry). The harbour popul...

This study examined the calcium transport properties of two subcellular fractions of bovine aorta obtained by differential centrifugation. The vesicular fraction had a high-affinity (Km = 1.05 X 10(-6)M) calcium transport mechanism which could be potentiated by using the calcium-precipitating anion, oxalate. The mitochondria-enriched fraction's calcium transport system had a lower affinity for ...

Ferrochelatase (FECH) is an essential enzyme for the final step of heme biosynthesis. In green plants, its activity has been reported in both plastids and mitochondria. However, the precise subcellular localization of FECH remains uncertain. In this study, we analyzed the localization of FECH in the unicellular red alga, Cyanidioschyzon merolae. Immunoblot and enzyme activity analyses of subcel...

Monoclonal antibodies against rat liver mitochondrial phospholipase A2 were used to develop a rapid immunoaffinity chromatography for enzyme purification. The purified enzyme showed a single band upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The sequence of the N-terminal 24 amino acids was determined. This part of the sequence showed only 25% homology with that of rat pancrea...

Sionnnary. A comiparative study was made of the efffects of auxin (a-naphthalene acetic acid), kinetin (6-furfurylaminopurine) and a mixture of auxin and kinetin applied in vivo on synthesis okf RNA and protein and the distribution of such synthesis am'ongst the subcellular fractions of sections of endocarp from Kentucky Wonder pole beans (Phascolus vulgaris, L.). Auxin caused considerable enha...

A neutral triacylglycerol lipase activity that is separate and distinct from lipoprotein lipase (LPL) could be measured in homogenates of myocardial cells if protamine sulphate and high concentrations of albumin were included in the assay. This neutral lipase was predominantly particulate, with the highest relative specific activity in microsomal subcellular fractions. The induction of diabetes...

Immune precipitation analysis of pulse-labeled proteins present in subcellular fractions of mouse embryo cells infected with Moloney murine leukemia virus showed the presence of anti-gp70 serum-precipitable viral envelope gene products mainly in the microsomal fractions of these cells. In contrast, anti-p30 serum-specific gag (group specific antigen) gene products were found to be distributed i...