Sialidases cytosolic

Chavas LMG, Tringah C, Fusi P, Venerando B, Tettamanti G, Kato R, Monti E, Wakatsuki S (2005) Crystal structure of the human cytosolic sialidase Neu2. Evidence for the dynamic nature of substrate recognition. J Biol Chem 280 469-475... 

Three enzyme systems are required for the catabolism of sialic acids 0-acetylesterases, sialidases and lyases. Furthermore, a sialic acid transporter has been described (section 10.5), which carries liberated sialic acids from lysosomes into the cytosol, where they are either degraded by the lyase or recycled after activation with CTP (section 8.3). Sialic acid permeases provide bacteria with sialic acids for nutritional purposes (section 9.4). 

After binding, T. cruzi enters host cells via an acidic vacuole, which fuses with lysosomes [818,844-846]. The parasitophorous vacuole formed in this way is later disrupted in order to release the trypanosomes into the cytosol. 7ra j-sialidase activity seems to be required for the latter step, as it desialylates the highly sialylated lysosomal... 

The fourth member of the mammalian sialidase family, NEU4, has been identified by searching sequence databases for entries showing homologies to human cytosolic sialidase One peeuliar feature of this enzyme is the presence of a long... 

T. Miyagi, K. Konno, Y. Emori, H. Kawasaki, K. Suzuki, A. Yasui, and S. Tsuik, Molecular cloning and expression of cDNA encoding rat skeletal muscle cytosolic sialidase, J. Biol. Chem., 268 (1993) 26435-26440. 

S. Marchesini, Overexpression of cytosolic sialidase Neu2 induces myoblast differentiation in C2C12 cells, FEBS Lett, 547 (2003) 183-188. 

A. Fanzani, F. Colombo, R. Giuliani, A. Preti, and S. Marchesini, Insulin-like growth factor 1 signaling regulates cytosolic sialidase Neu2 expression during myoblast differentiation and hypertrophy, FEBS J., 273 (2006) 3709-3721. 

S. Rossi, E. Stoppani, W. Martinet, A. Bonetto, R Costelli, R. Giuliani, F. Colombo, A. Preti, S. Marchesini, and A. Fanzani, The cytosolic sialidase Neu2 is degraded by autophagy during myoblast atrophy, Biochim. Biophys. Acta, 1790 (2009) 817-828. 

Crystal structure of the human cytosolic sialidase Neu2. Evidence for the dynamic nature of substrate recognition. Journal of Biological Chemistry, 280, 469-475. 

Recently, a specific antibody against the purified cytosolic sialidase from rat skeletal muscle was prepared and its immunoreactivity with other sialidases examined (Miyagi et al., 1990b). The antibody completely immunoprecipitates the cytosolic enzyme in rat liver and skeletal muscle, but not the synaptosomal and lysosomal enzymes in rat brain and liver. These results suggest that a single cytosolic sialidase species may exist in rat tissues which is immunologically distinct from the lysosomal and plasma membrane enzymes. 

It has been reported that a neutral sialidase activity is associated with rat liver microsomal membranes and this activity can be released from the membranes with 0.5 M NaCl. The solubilized enzyme is indistinguishable from the cytosolic enzyme with respect to pH optima and values. Isotonic sucrose solution does not solubilize the enzyme. It appears that this enzyme may represent cytosolic enzyme which is adsorbed onto the membranes (Miyagi and Tsuiki, 1985). 

Previous studies have demonstrated the presence of two different forms of sialidase in the cytosol of pig brain (Venerando etal., 1975). The sialidase activity... 

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