Cathepsin X has been reported to be a tumor promotion factor in various types of cancer; however, the molecular mechanisms linking its activity with malignant processes are not understood. Here we present profilin 1, a known tumor suppressor, as a target for cathepsin X carboxypeptidase activity in prostate cancer PC-3 cells. Profilin 1 co-localizes strongly with cathepsin X intracellularly in ...

Regulation of pollen tube growth is known to involve alterations in intracellular calcium levels and phosphoinositide signaling, although the mechanisms involved are unclear. However, it appears likely that pollination events involve a complex interplay between signaling pathways and components of the actin cytoskeleton in pollen. In many eukaryotic cells, actin binding proteins function as sti...

We present evidence that native profilin can be purified from cellular extracts of Acanthamoeba, Dictyostelium, and human platelets by affinity chromatography on poly-L-proline agarose. After applying cell extracts and washing the column with 3 M urea, homogeneous profilin is eluted by increasing the urea concentration to 6-8 M. Acanthamoeba profilin-I and profilin-II can subsequently be separa...

We have analyzed the degree of functional similarity between birth and mammalian profilins, two members of the profilin family which show only a moderate sequence homology (22%) in living animal cells. The plant profilin, derived from birch pollen, was stably expressed in BHK-21 cells. Plant and endogenous profilin synthesis and cellular distribution were monitored by specific monoclonal antibo...

We characterized several deletion and substitution mutations of Acanthamoeba profilin and nine monoclonal antibodies to Acanthamoeba profilin. The results provide two independent lines of evidence about the binding sites for actin and poly-L-proline on the profilin molecule. This new evidence is consistent with the main conclusions about these binding sites from previous structural and mutageni...

Profilin i s a ubiquitous eukaryotic protein that regulates the actin cytoskeleton and recently has been identified as a potent allergen in pollen. We examined the profilin gene family i n the model plant, Arabidopsis thaliana, and found that it contained approximately 8 to 10 members. Four distinct profilin sequences, three cDNAs, PRF1, PRFZ, and PRF3, and two genomic clones, PRFl and P R M , ...

We have used a fluorescence assay to measure the binding of Acanthamoeba profilin to monomeric Acanthamoeba and rabbit skeletal muscle actin labeled on cysteine-374 with pyrene iodoacetamide. The wavelengths of the pyrene excitation and emission maxima are constant at 346 and 386 nm, but the fluorescence is enhanced up to 50% by profilin. The higher fluorescence is largely due to higher absorba...

BACKGROUND In birch pollen-allergic patients the occurrence of clinically relevant crossreactivity to plant-derived foods is clearly related with the level of birch-specific IgE. In profilin-hypersensitive patients this has not been investigated so far. OBJECTIVE To investigate whether the levels of profilin IgE are predictive of the development of food allergy in hypersensitive patients. M...

Membrane structures and cytoskeleton dynamics are intimately inter-connected in the eukaryotic cell. Recently, the molecular mechanisms operating at this interface have been progressively addressed. Many experiments have revealed that the actin cytoskeleton can interact with membranes through various discrete membrane domains. The actin-binding protein, profilin has been proven to inhibit actin...