Role of plasma membrane-bound sialidase NEU3 in clathrin-mediated endocytosis

RODRIGUEZ-WALKER M; VILCAES AA; GARBARINO PICO E; DANIOTTI JL

BIOCHEMICAL JOURNAL

PORTLAND PRESS LTD

Lugar: Londres; Año: 2015 vol. 470 p. 131 - 131

0264-6021

angliosides are sialic acid containing glycosphingolipids mainly expressed at the outer leaflet of the plasma membrane. Sialidase NEU3 is a key enzyme in the catabolism of gangliosides with its up-regulation having been observed in human cancer cells. In the case of clathrin-mediated endocytosis (CME), although this has been widely studied, the role of NEU3 and gangliosides in this cellular process has not yet been established. Here, we found an increased internalization of transferrin (Tf), the archetypical cargo for CME, in cells expressing complex gangliosides with high levels of sialylation. The ectopic expression of NEU3 led to a drastic decrease in Tf endocytosis, suggesting a participation of gangliosides in this process. However, the reduction of Tf endocytosis caused by NEU3 was still observed in glycosphingolipid-depleted cells, indicating that NEU3 could operate in a way that is independent of its action on gangliosides. Additionally, internalization of α2 macroglobuli