Cytoskeleton actin

Barbieri JT, Riese MJ, Aktories K (2002) Bacterial toxins that modify the actin cytoskeleton. Annu Rev Cell Dev Biol 18 315-344... 

Catenins are defined as cytoplasmic interaction partners of cadherins that form a chain of proteins ( catena, latin for chain), which connects cadherins to the actin cytoskeleton. 

Stimulation of PKA and PKC inhibit NHE5 activity, as does hyperosmolarity, resembling the responsiveness of NHE3. NHE5 may also be regulated by the actin cytoskeleton, but further work is required to validate this notion and clarify the exact mechanism. 

Hall, A. (1994). Small GTP-binding proteins and the regulation of the actin cytoskeleton. Ann. Rev. Cell Biol. 10,31-54. 

Fig. 2.3 The development of polarity and asymmetric division in Saccharomyces cerevisiae. The diagram is reproduced in a slightly simplified form from the work of Lew Reed (1995) with the permission of Current Opinion in Genetics and Development, (a) The F-actin cytoskeleton strands = actin cables ( ) cortical actin patches, (b) The polarity of growth is indicated by the direction of the arrows (arrows in many directions signifies isotropic growth), (c) 10-nm filaments which are assembled to form a ring at the neck between mother and bud. (d) Construction of the cap at the pre-bud site. Notice that the proteins of the cap become dispersed at the apical/isotropic switch, first over the whole surface of the bud, then more widely. Finally, secretion becomes refocussed at the neck in time for cytokinesis, (e) The status and distribution of the nucleus and microtubules of the spindle. Notice how the spindle pole body ( ) plays an important part in orientation of the mitotic spindle.

The role of tyrosine kinase signaling in actin cytoskeleton regulation is well established (166-171), and certain steps in the activation pathways of both Rac 1 and RhoA, two molecules known to modulate actin function, may also require tyrosine kinase activity (172,173). In fact, two recent reports have also indicated... 

Chrzanowska-Wodnicka M, Burridge K. Tyrosine phosphorylation is involved in reorganization of the actin cytoskeleton in response to serum or LPA stimulation. J Cell Sci 1994 107(Pt 12) 3643-3654. 

Campbell EM, Nunez R, Hope TJ. Disruption of the actin cytoskeleton can complement the ability of Nef to enhance human immunodeficiency virus type 1 infectivity. J Virol 2004 78(ll) 5745-5755. 

C. difficile history of antibiotic use, advanced age, underlying illness 5-10 days of antibacteria treatment (range 1st day to 10 weeks of antibiotics) mild to severe inflammatory diarrhea toxins A and B monoglucosylation of Rho protein - disruption of actin cytoskeleton —> mucosal disruption. - COX-2 - prostaglandin E2 —> synthesis of inflammatory cytokines... 

Di Campli, A., Valderrama, F., Babia, T., De Matteis, M. A., Luini, A. and Egea, G. Morphological changes in the Golgi complex correlate with actin cytoskeleton rearrangements. Cell Motil. Cytoskeleton 43 334-348,1999. 

A third type of bacterial toxin, diphtheria toxin, catalyzes the ADP-ribosylation of eukaryotic elongation factor (EFTU), a type of small G protein involved in protein synthesis (Table 19-2). The functional activity of the elongation factor is inhibitedby this reaction. Finally, a botulinum toxin ADP-ribosylates and disrupts the function of the small G protein Rho, which appears to be involved in assembly and rearrangement of the actin cytoskeleton (Table 19-2). These toxins maybe involved in neuropathy (see Ch. 36) and membrane trafficking (see Ch. 9). 

Parker KE 1998 Modulation of ATP-gated non-selective cation channel (P2X1 receptor) activation and desensitization by the actin cytoskeleton. J Physiol 510 19—25... 

The family of eukaryotic Ras-like small GTPases may be divided into subfamilies, namely those of ARF, Rab, Ran, Ras, Rho, and Sar (ARF, RAB, RHO, RAS, RHO, SAR), which all contain representatives from fungi, plants, and metazoa. Consequently, these subfamilies and their cellular functions are likely to have emerged early in eukaryotic history. This implies that the last common ancestor of fungi, plants, and metazoa possessed vesicular transport (ARF and Sar), membrane trafficking (Rab), nuclear transport (Ran), signal transduction (Ras), and regulation of the actin cytoskeleton (Rho) functions. 

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