The immunohistochemical localization of actin, vimentin and tubulin in adult ovine and bovine seminiferous tubules was studied at both the light and electron microscopical levels, using an improved methodical protocol. alpha-smooth muscle actin and structural F-actin were found to be present in myoid peritubular cells. Structural F-actin also occurs in Sertoli cells at three localizations; 1) A...

N-Phenyl-N'-(2-chloroethyl)ureas (CEUs) are antimicrotubule agents interacting covalently with β-tubulin near the colchicine-binding site (C-BS). Glutamyl 198 residue in β-tubulin (Glu198), which is adjacent to the C-BS behind the two potent nucleophilic residues, Cys239 and Cys354, has been shown to covalently react with 1-(2-chloroethyl)-3-(4-iodophenyl)urea (ICEU). By use of mass spectrometr...

The authors compared cytoskeletal elements of the in situ human trabecular-meshwork cell with in situ human corneal cells using indirect immunofluorescence staining for tubulin and intermediate filaments (vimentin, cytokeratin, and desmin) and NBD-phallacidin staining for f-actin using both fixed frozen and unfixed frozen sections from postmortem eyes. Both f-actin and tubulin were found throug...

We have been able to visualize cytoskeletal messenger RNA molecules at high resolution using nonisotopic in situ hybridization followed by whole-mount electron microscopy. Biotinated cDNA probes for actin, tubulin, or vimentin mRNAs were hybridized to Triton-extracted chicken embryo fibroblasts and myoblasts. The cells were then exposed to antibodies against biotin followed by colloidal gold-co...

PURPOSE Previous studies have identified the cytoskeletal proteins actin and tubulin as potential cellular targets in the trabecular meshwork for novel glaucoma therapy. The authors and others have hypothesized that acto-myosin interactions may be important for outflow function. The current study was conducted to evaluate 2,3-butanedione 2-monoxime (BDM), a compound that interferes with acto-my...

Obesity is an important risk factor for intervertebral disc degeneration and leptin is a biomarker of obesity. However, the expression of leptin receptors has not been determined in disc tissue. It is not known whether leptin has a direct effect on the nucleus pulposus (NP) cells. To determine whether the NP tissues and cells express leptin receptors (OBRa and OBRb) and whether leptin affects t...

Bilateral ureteral obstruction (BUO) is associated with renal damage and impaired ability to concentrate urine and is known to induce alterations in an array of kidney proteins. The aim of this study was to identify acute proteomic alterations induced by BUO. Rats were subjected to BUO for 2, 6, or 24 h. Mass spectrometry-based proteomics was performed on the renal inner medulla, and protein ch...

P latelets, the anucleate progeny of bone marrow megakaryocytic cells, are well known as the primary cellular agents of hemostasis. Pioneering efforts over the past decade have visualized the manner in which megakaryocytes give rise to platelets through a carefully orchestrated branching, budding, and release of proplatelet appendages. In their later stages of maturation, megakaryocytes extend ...

microtubule-kinesin system and the actin-myosin system Both systems operate on the same principle; myosin or kinesin motor heads drive specific polymer filaments ma up of protein monomers (actin or tubulin) while utilizing ATP as a chemical energy source (Figure 1 [1]). Actin monomers have an average length of 5.5 nm and join together to form twisted-rope chains 10 nm in diamet with lengths of ...

We describe the discovery of a heterohexameric chaperone protein, prefoldin, based on its ability to capture unfolded actin. Prefoldin binds specifically to cytosolic chaperonin (c-cpn) and transfers target proteins to it. Deletion of the gene encoding a prefoldin subunit in S. cerevisiae results in a phenotype similar to those found when c-cpn is mutated, namely impaired functions of the actin...