The HEAT repeat domain is a solenoid protein domain found in a number of cytoplasmic proteins including the four that the give rise to the acronym HEAT (Huntingtin, elongation factor 3 (EF3), protein phosphatase 2A (PP2A), and the yeast kinase TOR1). HEAT repeats form rod-like helical structures which are involved in intracellular transport.
^Groves MR, Hanlon N, Turowski P, Hemmings BA, Barford D (January 1999). "The structure of the protein phosphatase 2A PR65/A subunit reveals the conformation of its 15 tandemly repeated HEAT motifs". Cell96 (1): 99–110. doi:10.1016/S0092-8674(00)80963-0. PMID9989501.