Disease relevance of LOC443340

• Carcinoid valve cusps demonstrated the unusual finding of widespread smooth muscle actin involving the interstitial cells in the periphery of carcinoid nodules; these same cells were also positive for LAP [1].
• Furthermore, plasma from patients with ARDS secondary to bacterial pneumonia is toxic to SPAEC, and a small but significant contributory role of actin is apparent in these studies [2].
• Actin released from damaged cells after a variety of tissue injuries appears to be involved in multiple organ dysfunction syndrome [2].
• However, an E. coli O157:H7 tccP mutant induced typical attaching and effacing lesions in a bovine ligated ileal loop model of infection, suggesting that TccP-independent mechanisms of actin assembly may operate in vivo [3].
• CONCLUSION: The onset of proteinuria in the PHN model of MN is coincident with complement-dependent alterations in the association of nephrin with the actin cytoskeleton and loss of podocyte slit diaphragm integrity [4].

High impact information on LOC443340

• This surprising effect is made possible by the involvement of the irreversible ATP hydrolysis accompanying actin polymerization [5].
• Similarly, wortmannin and LY294002 did not inhibit the extension of actin-rich pseudopodia along IgG-opsonized sheep erythrocytes, but instead prevented them from closing into phagosomes [6].
• Muscle actin purified from rabbit back and leg muscles and labeled with fluorescein isothiocyanate, and nonmuscle actin purified from lamb brain and labeled with lissamine rhodamine B sulfonyl chloride, were co-injected into chick embryonic cardiac myocytes and fibroblasts [7].
• Actin in the photoreceptor connecting cilium: immunocytochemical localization to the site of outer segment disk formation [8].
• Actin has been localized in Rana pipiens retinas that were fixed and embedded in aldehyde cross-linked BSA [8].

Chemical compound and disease context of LOC443340

• Complement mediates nephrin redistribution and actin dissociation in experimental membranous nephropathy [4].
• OBJECTIVE: We studied the effect of long-term, high-altitude hypoxia on cardiac myosin, actin, and troponin T (TnT) isoforms and Ca(2+)- and Mg(2+)-activated myofibrillar adenosine triphosphatase (ATPase) activities in fetal and adult sheep [9].
• Angiotensin II stimulation of granuloma macrophage phagocytosis and actin polymerization in murine schistosomiasis mansoni [10].

Biological context of LOC443340

• Chimeric transmembrane proteins bearing syk but not src family tyrosine kinase domains are capable of autonomously triggering phagocytosis and redistribution of filamentous actin in COS cells [11].
• Controls included parallel hybridizations with a 35S-labeled gamma-actin cDNA to detect actin mRNA (positive control) and with 35S-labeled plasmid cDNA (negative control) [12].
• Purity of smooth muscle cell cultures at each vascular site was assessed by the "hills and valleys" phenotype and by positive immunofluorescence with a smooth muscle actin specific monoclonal antibody [13].
• Coordinated regulation of synapsin I interaction with F-actin by Ca2+/calmodulin and phosphorylation: inhibition of actin binding and bundling [14].
• This protein fraction which stimulates FPCL contraction is not related to 1) actin-myosin filaments enhanced contraction by ATP-induced cell contraction, 2) promotion of fibroblast elongation on glass surface or in collagen, or 3) increased cell number by enhanced fibroblast duplication in a collagen matrix [15].

Anatomical context of LOC443340

• Cytochalasin D, an inhibitor of actin assembly and polymerization, abolished phagocytic activity in both control and beta-interferon-treated macrophages [16].
• These results imply that in resting platelets and neutrophils, actin is sequestered by T beta 4 as MgATP-G-actin [17].
• Methylamine protection experiments and immunofluorescence studies suggested that CNF2 enters the cytosol of the target cell through an acidic compartment and induces the reorganization of actin into stress fibers [18].
• Normal valve cusps were only focally positive for smooth muscle actin and LAP [1].
• An actin assay which employs the competition between labeled and unlabeled rabbit skeletal muscle actin for DNase I has been developed [19].

Associations of LOC443340 with chemical compounds

• At low concentrations the incorporation was comparable to that of dimethyl casein and much greater than actin or fibrinogen [20].
• Western blot analysis of the glomerular extracts showed a significant reduction in the total amount of nephrin and in the fraction of actin-associated nephrin in the PHN group, whereas the amounts in the complement-depleted rats were similar to normal controls [4].
• In both adult and fetal middle cerebral artery, cytochalasin D-induced inhibition of actin polymerization decreased PHE-induced contraction, to approximately 60 and approximately 40% of control, respectively (despite no significant change in expression level) [21].
• Actin, MHC, and MHC isoforms were analyzed by SDS-PAGE using 3-20% and 4% polyacrylamide gels, respectively [22].
• Incubation of sperm in media lacking BSA or methyl-beta-cyclodextrin, Ca(2+), or NaHCO(3), components that are all required for capacitation, prevented actin polymerization as well as capacitation, as assessed by the ability of the cells to undergo the acrosome reaction [23].

Physical interactions of LOC443340

• Under the conditions of our assay (0.45 microM synapsin I, 4 microM F-actin), half-maximal inhibition of actin binding and bundling by unphosphorylated synapsin I was found with 4.3 and 3.7 microM calmodulin, respectively [14].

Enzymatic interactions of LOC443340

• The actin binding activity of synapsin I phosphorylated by cAMP-dependent protein kinase or by calmodulin-dependent protein kinase II showed similar sensitivity to calmodulin inhibition to unphosphorylated synapsin I [14].

Regulatory relationships of LOC443340

• Treatment of cultured cardiac fibroblasts with transforming growth factor-beta (10 ng/ml) induced the expression of alpha-smooth muscle actin, characteristic of the transformation to myofibroblasts, and raised ANP concentrations in the medium [24].
• Filamin (0.007:actin) also decreased the inhibitory action of caldesmon on actin-activated myosin ATPase and also potentiated the reversal of this inhibition by calmodulin [25].

Other interactions of LOC443340

• Total RNA was subjected to Northern analysis using specific complementary DNA probes to CRH and POMC, and specific message was normalized to actin mRNA content in each individual sample [26].
• Day 15 pregnant ewes had lower expression of ER, PR, GAPDH, cyclophilin and actin genes [27].
• The interactions of vascular smooth muscle caldesmon with actin, tropomyosin, and calmodulin were determined under conditions in which the four proteins can form reconstituted Ca2+-sensitive smooth muscle thin filaments [28].
• Actin, tropomyosin, caldesmon and calponin were present in molar ratios 14:2:1:0 [29].
• By 2D gel map comparison and Western blotting, we identified transferrin, secreted by the yolk sac from Day 15, and cytoplasmic actin, one of the most abundant proteins produced by the trophoblast at Day 17 [30].

Analytical, diagnostic and therapeutic context of LOC443340

• A DNase I binding/immunoprecipitation assay for actin [19].
• Analysis of polyacrylamide gel electrophoresis (PAGE) gels of mature ovarian homogenates demonstrates that this protein is more abundant than actin in these preparations [31].
• Morphometric analysis and alpha-smooth muscle actin immunohistochemistry were performed on histological specimens from formalin fixed kidneys [32].
• By using in situ hybridization to tissue sections and dot-blot analysis of tissue extracts with labeled cDNA probes, it was shown that the quantity of oTP-1 mRNA fell 3- to 5-fold during culture, whereas the amount of actin mRNA remained relatively constant [33].
• RESULTS: Primary cell cultures stained positive for desmin and alpha-smooth muscle actin, confirming a smooth muscle origin [34].

References