ARM - Armadillo Repeat Motif from beta-Catenin

beta-Catenin is colored red, except for one ARM at the C-terminus which is colored blue. Beta-Catenin is shown bound to a phosphorylated peptide from APC, shown in yellow, spacefilling. The four phospho-serines are colored magenta.


Mechanism of phosphorylation-dependent binding of APC to beta-catenin and its role in beta-catenin degradation.
Ha NC, Tonozuka T, Stamos JL, Choi HJ, Weis WI.
Mol Cell. 2004 Aug 27;15(4):511-21.

(PubMed)

1v18 (PDB)

Armadillo-repeat protein functions: questions for little creatures.
Tewari R, Bailes E, Bunting KA, Coates JC.
Trends Cell Biol. 2010 Aug;20(8):470-81.

Abstract
Armadillo (ARM)-repeat proteins form a large family with diverse and fundamental functions in many eukaryotes. ARM-repeat proteins have largely been characterised in multicellular organisms and much is known about how a subset of these proteins function. The structure of ARM-repeats allows proteins containing them to be functionally very versatile. Are the ARM-repeat proteins in 'little creatures' as multifunctional as their better-studied relatives? The time is now right to start analysing ARM-repeat proteins in these new systems to better understand their cell biology. Here, we review recent advances in understanding the many cellular roles of both well-known and novel ARM-repeat proteins.

Armadillo repeat proteins: beyond the animal kingdom.
Coates JC.
Trends Cell Biol. 2003 Sep;13(9):463-71

Abstract
Armadillo (Arm) repeat proteins contain tandem copies of a degenerate protein sequence motif that forms a conserved three-dimensional structure. Animal Arm repeat proteins function in various processes, including intracellular signalling and cytoskeletal regulation. A subset of these proteins are conserved across eukaryotic kingdoms, and non-metazoa such as Dictyostelium and Chlamydomonas possess homologues of members of the animal Arm repeat family. Higher plants also possess Arm repeat proteins, which, like their animal counterparts, function in intracellular signalling. Notably, these plant Arm proteins have novel functions. In addition, genome sequencing has identified a plethora of Arm-related proteins in Arabidopsis.