I-cell cultured fibroblasts secrete excessive amounts of N-acetyl-fl-D-hexosaminidase and a -L-fucosidase into the culture media as compared with normal fibroblasts. Addition of tunicamycin or cycloheximide at doses that inhibit the incorporation of [3Hlmannose (60-80%) and [14C]leucine (40-50%) into trichloroacetic acid-precipitable material decreased the secretion of these I-cell hydrolases t...

Cystine depleted cystinotic fibroblasts incubated in cystine-free medium accumulate lysosomal-free cystine from the degradation of cystine-containing intracellular and extracellular proteins. In this report we have used this characteristic of these cells to study lysosomal proteolysis. We find that inhibitors of protein synthesis (cycloheximide, emetine, and puromycin) inhibit cystine accumulat...

The signal recognition particle (SRP) binds to ribosomes that synthesize nascent chains bearing signal sequences and catalyzes their targeting to the endoplasmic reticulum membrane. In S. cerevisiae, a temperature-sensitive mutation in the SEC65 gene, encoding an SRP subunit, results in lowered levels of SRP. Growth and protein translocation defects induced by this mutation can be suppressed sp...

Three new cycloheximide congeners, 2,3-dehydro-α-epi-isocycloheximide (1), (E)- and (Z)-2,3-dehydroanhydrocycloheximides (2 and 3), together with three known compounds, anhydroisoheximide (4), cycloheximide (5), and isocycloheximide (6), were obtained from the cultures of Streptomyces sp. SC0581. Their structures were elucidated by extensive spectroscopic analysis in combination with theoretica...

Bitter taste perception provides animals with critical protection against ingestion of poisonous compounds. In the accompanying paper, we report the characterization of a large family of putative mammalian taste receptors (T2Rs). Here we use a heterologous expression system to show that specific T2Rs function as bitter taste receptors. A mouse T2R (mT2R-5) responds to the bitter tastant cyclohe...

Exogenous plasma and endogenous cellular fibronectins on the surface of cultured fibroblasts and in extracellular matrix fibrils were colocalized by fluorescent and high voltage immunoelectron microscopy. Fibroblast cultures grown in the presence or absence of cycloheximide were incubated with exogenous plasma fibronectin labeled with fluorescein isothiocyanate. A monoclonal antibody specific f...

A dominant mutation at a new locus affecting resistance to cycloheximide has been isolated by exploiting a synergistic relationship with a previously known mutation for cycloheximide resistance in Tetrahymena. The new mutation (ChxB) was induced in a line homozygous for ChxA and was recovered from that background by a new technique termed interrupted genomic exclusion. Segregation data from the...

The present study was aimed at determining the functionally essential size of the neuronal population in the central olfactory nervous system. Using conditioned rats who had learnt to avoid repellent (cycloheximide) solution by olfaction, varying degrees of injuries were made to the lateral olfactory tract, a major central olfactory pathway connecting the olfactory bulb to the olfactory cortex....

The role of protein synthesis in auxin-induced cell elongation in lupin hypocotyl segments was studied using cycloheximide. Cycloheximide inhibited protein synthesis by 9 minutes. Experiments adding cycloheximide at various times before and after indolyl-3-acetic acid are reported. Estimates of the relative amounts of growth-limiting protein(s), and a first order rate constant for the apparent ...

The ability of antibiotics to inhibit acetylcholinesterase was measured in homogenates of goldfish brain. Puromycin aminonucleoside was the most potent inhibitor followed by puromycin, cycloheximide and acetoxycycloheximide. Puromycin effectively impaired retention of active-avoidance learning in goldfish when injected either immediately before or after training, while puromycin aminonucleoside...