The acetyl-CoA transporter family SLC33

Abstract

The acetyl-CoA (Ac-CoA) transporter, ACATN is a multiple (11 or 12) transmembrane protein in the endoplasmic reticulum. Ac-CoA is transported into the lumen of the endoplasmic reticulum/Golgi apparatus, where it serves as the substrate of acetyltransferases that modify a variety of molecules including the sialic acid residues of gangliosides and lysine residues of membrane proteins. The ACATN gene, assigned as SLC33A1, was cloned from human melanoma cells and encodes the ACATN/ACATN1 (Acetyl-CoA Transporter 1) protein. Although homologs of this family of proteins have been identified in lower organisms such as Escherichia coli, Drosophila melanogaster and Caenorhabditis elegans, only one member of this SLC33A1 family has been identified. Although acetylated gangliosides are synthesized in the luminal Golgi membrane and show a highly tissue-specific distribution, ACATN1 is enriched in the ER membrane and is ubiquitously expressed. Phylogenetically, the SLC33A1 gene is highly conserved, suggesting that it is particularly significant. In fact, ACATN1 is essential for motor neuron viability. SLC33A1 is associated with neurodegenerative disorders such as sporadic amyotrophic lateral sclerosis (ALS) and Spastic Paraplegia 42, in the Chinese population.