Involved in the synthesis of gangliosides GD1c, GT1a, GQ1b, GP1c and GT3 from GD1a, GT1b, GM1b and GD3 respectively. CMP-N-acetyl-beta-neuraminate + ganglioside GT1b (d18:1(4E)) = CMP + ganglioside GQ1b (d18:1(4E)) + H(+) CMP-N-acetyl-beta-neuraminate + ganglioside GD3 (d18:1(4E)) = CMP + ganglioside GT3 (d18:1(4E)) + H(+) CMP-N-acetyl-beta-neuraminate + ganglioside GD1a (d18:1(4E)) = CMP + ganglioside GT1a (d18:1(4E)) + H(+) CMP-N-acetyl-beta-neuraminate + ganglioside GM1b (d18:1(4E)) = CMP + ganglioside GD1c (d18:1(4E)) + H(+) CMP-N-acetyl-beta-neuraminate + ganglioside GQ1c (d18:1(4E)) = CMP + ganglioside GP1c (d18:1(4E)) + H(+) Protein modification; protein glycosylation. Highly expressed in brain. Expressed at low levels in other tissues, including liver, testis, lung, placenta and spleen. First detected at 14 dpc, expression increases until at least 7 weeks after birth. Belongs to the glycosyltransferase 29 family. ST8Sia V