title: HEAT repeats - versatile arrays of amphiphilic helices working in crowded environments?
abstract: Cellular proteins do not work in isolation. Instead, they often function as part of large macromolecular complexes, which are transported and concentrated into specific cellular compartments and function in a highly crowded environment. A central theme of modern cell biology is to understand how such macromolecular complexes are assembled efficiently and find their destinations faithfully. In this Opinion article, we will focus on HEAT repeats, flexible arrays of amphiphilic helices found in many eukaryotic proteins, such as karyopherins and condensins, and discuss how these uniquely designed helical repeats might underlie dynamic protein-protein interactions and support cellular functions in crowded environments. We will make bold speculations on functional similarities between the action of HEAT repeats and intrinsically disordered regions (IDRs) in macromolecular phase separation. Potential contributions of HEAT-HEAT interactions, as well as cooperation between HEATs and IDRs, to mesoscale organelle assembly will be discussed.
authors: Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan yoshimura@lif.kyoto-u.ac.jp hiranot@riken.jp.
authors: Shige H
authors: SH
authors: Yoshimura
authors: Chromosome Dynamics Laboratory, RIKEN, Saitama 351-0198, Japan yoshimura@lif.kyoto-u.ac.jp hiranot@riken.jp.
authors: Tatsuya
authors: 0000-0002-4219-6473
authors: T
authors: Hirano
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006801:Humans; D064267:Intrinsically Disordered Proteins / Q000737:chemistry; D008938:Mitosis; D017433:Protein Structure, Secondary; D021381:Protein Transport; D020449:Repetitive Sequences, Amino Acid; D017386:Sequence Homology, Amino Acid
chemical_list: D064267:Intrinsically Disordered Proteins
keywords: Condensin; HEAT repeat; Hydrogel; IDR; Karyopherin; Molecular crowding; Phase separation