ATRNL1 is a 1,379 amino acid single-pass type I membrane protein that may play a role in melanocortin signaling pathways that regulate energy homeostasis. The ATRNL1 protein contains a C-type lectin domain, a CUB domain, two EGF-like domains, six Kelch repeats, two laminin EGF-like domains and five PSI domains. ATRNL1 interacts with MC4-R in several regions known to be important in the regulation of energy homeostasis by melanocortins, such as the paraventricular nucleus of hypothalamus and the dorsal motor nucleus of the vagus. The ATRNL1 gene is conserved in dog, cow, mouse, rat, chicken, zebrafish and C. elegans, exists as two alternatively spliced isoforms and maps to human chromosome 10q25.3. Strong evidence of linkage to late-onset Alzheimer disease (LOAD) is linked to chromosome 10, which implicates a wide region and at least one disease-susceptibility locus.