Acetyl-CoA transporter that mediates active acetyl-CoA import through the endoplasmic reticulum (ER) membrane into the ER lumen where specific ER-based acetyl-CoA:lysine acetyltransferases are responsible for the acetylation of ER-based protein substrates, such as BACE1 (PubMed:20826464, PubMed:24828632). Necessary for O-acetylation of gangliosides (PubMed:9096318). {ECO:0000269|PubMed:20826464, ECO:0000269|PubMed:24828632, ECO:0000269|PubMed:25402622, ECO:0000269|PubMed:9096318}. This is the function of Ensembl gene identifier ENSG00000169359 (SLC33A1, solute carrier family 33 member 1).