Gelsolin

Non-EF-hand Ca2+-binding proteins including the annexins, C2-domain proteins, and gelsolin, and the EF-hand Ca2+-binding proteins. 

Lewy bodies are typical in neuronal degeneration, which is accompanied by the presence of these eosinophilic intracellular inclusions of 5-25 pm diameter in a proportion of still surviving neurons. Lewy bodies contain neurofilament, tubulin, microtubule-associated proteins 1 and 2, and gelsolin, an actin-modulating protein. 

Barbed-end-capping proteins (gelsolin and villin, 95 kD) attach to this specific end of the actin filament and inhibit the further addition of actin molecules. 

Coue, M. Kom, E.D. (1985). Interaction of plasma gelsolin with G-actin and F-actin in the presence and absence of Ca ions. J. Biol. Chem. 260, 15033-15041. 

Gelsolin Vert. Fibroblast increased 2x increased rate Cunningham et al., 1991... 

Cunningham, C.C., Stossel, T.P., Kwiatowski, D.J. (1991). Enhanced motility in NIH 3T3 fibroblasts that overexpress gelsolin. Science, 251, 1233-1236. 

Kwiatkowski DJ. Functions of gelsolin motility, signaling, apoptosis, cancer. Curr Opin Cell Biol 1999 11(1) 103-108. 

Weeds AG, Gooch J, McLauglin P, Pope B, Bengtsdotter M, Karlsson R. Identification of the trapped calcium in the gelsolin segment 1-actin complex implications for the role of calcium in the control of gelsolin activity. FEBS Lett 1995 360 227-230. 

Actin, spectrin, tau, vimentin, P-catenin, gelsolin, kinectin... 

AP and tau, 6-2 microglobulin Immunoglobulin light chain Serum amyloid A (SAA) Transthyretin (TTR) Apolipoprotein A-l Cystatin A Gelsolin... 

Gelsolin blocks barbed ends of actin filaments 84 Ca2+,PIP2... 

If the cross-links or polymers are severed, then some elastic energy is released and the system will adopt a new (larger) equilibrium volume where greater distortion is conferred upon a meshwork that has fewer cross-links. Thus, upon increases in Ca2+, gelsolin activity leads to an increase in the volume of the actin-filament network. The additional influence of myosin on such a meshwork is similar to that proposed in the Stossel model. Thus, three-dimensional Ca2+ gradients (between a localised region of the cell surface and an external structure) can result in complex shape changes. 

Growth-Arrest-Specific protein 2 Domain Gastrin/cholecystokinin/caerulein family Dynamin GTPase effector domain Gelsolin homology domain G protein y subunit-like motifs Glycoprotein hormone a chain homologs... 

Caspase-mediated cleavage of specific substrates can explain several of the characteristic features of apoptosis. For example, cleavage of the nuclear lamins and cytoplasmic proteins such as fodrin and gelsolin are required for nuclear and cellular... 

Figure 3. Critical concentration behavior of actin self-assembly. For the top diagram depicting the macroscopic critical concentration curve, one determines the total amount of polymerized actin by methods that measure the sum of addition and release processes occurring at both ends. Examples of such methods are sedimentation, light scattering, fluorescence assays with pyrene-labeled actin, and viscosity measurements. Forthe bottom curves, the polymerization behavior is typically determined by fluorescence assays conducted under conditions where one of the ends is blocked by the presence of molecules such as gelsolin (a barbed-end capping protein) or spectrin-band 4.1 -actin (a complex prepared from erythrocyte membranes, such that only barbed-end growth occurs). Note further that the barbed end (or (+)-end) has a lower critical concentration than the pointed end (or (-)-end). This differential stabilization requires the occurrence of ATP hydrolysis to supply the free energy that drives subunit addition to the (+)-end at the expense of the subunit loss from the (-)-end.

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