Neutral amino acid transporter A is a protein that in humans is encoded by the SLC1A4 gene. In humans, it is expressed in the brain, lung, skeletal muscle, intestine and kidney.

The transporter is responsible for transport of L-serine, D-serine, L-alanine, L-cysteine, and L-threonine.

Mutations of the gene cause a disease called spastic tetraplegia, thin corpus callosum, and progressive microcephaly (SPATCCM). This disorder is inherited in an autosomal recessive fashion.

In melanocytic cells SLC1A4 gene expression may be regulated by MITF.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.