HEAT Repeat Containing Protein 5B (HEATR5B)

HEATR5B (HEAT repeat containing 5B) is a 2,071 amino acid protein belonging to the HEATR5 family. HEATR5B exists as three alternatively spliced isoforms and consists of three HEAT (huntingtin, elongation factor 3 (EF3), protein phosphatase 2A (PP2A) and the yeast PI 3-kinase Tor1) repeats. HEAT repeats form rod-like helical structures that are involved in intracellular transport. HEATR5B is encoded by a gene located on human chromosome 2, which houses over 1,400 genes and comprises nearly 8% of the human genome. Harlequin icthyosis, a rare and morbid skin deformity, is associated with mutations in the chromosome 2-localized ABCA12 gene, while the lipid metabolic disorder sitosterolemia is associated with defects in the ABCG5 and ABCG8 genes, which also map to chromosome 2.