Chp‐1 and melusin, two CHORD containing proteins in vertebrates

Abstract

Melusin is a muscle speci¢c protein required for heart hypertrophy in response to mechanical overload. Here we describe a protein 63% homologous to melusin, named chp-1, expressed in all tissues tested, including muscles, and highly conserved from invertebrates to human. Both proteins are characterized in their N-terminal half by a tandemly repeated zinc binding 60 amino acid domain with a motif of uniquely spaced cysteine and histidine residues. These motives are highly conserved from plants to mammals and have been recently named CHORD (for cysteine and histidine rich domain) domains. At the C-terminal end melusin contains a calcium binding stretch of 30 acidic amino acid residues which is absent in chp-1. While invertebrate genome contains only one gene coding for a chp-1 homolog, two genes coding for CHORD containing proteins (chp-1 and melusin) are present in vertebrates. Sequence analysis suggests that the muscle speci¢c CHORD containing protein melusin originated by a gene duplication event during early chordate evolution. ß

MicroRNA-26b Inhibits Hepatitis B Virus Transcription and Replication by Targeting the Host Factor CHORDC1 Protein

“…CHORDC1, also called CHP1 or morgana, is one of only two genes encoding this class of proteins in vertebrates (37,38). Mammalian CHORDC1 is a novel heat-shock protein 90 (HSP90) co-chaperone, and this interaction may be involved in the response to altered energy balance (39 -41).…”

SGT1 is essential for Nod1 activation

“…The plant protein Rar1 has been shown to associate with SGT1 and HSP90 and is required for the function of some R proteins (14,18). A mammalian orthologue of RAR1, Chp1, has been identified but its function is unknown (19). We next asked whether we could establish a role for Chp1 in Nod1-dependent signaling (Fig.…”

“…In plants, some R protein pathways require both SGT1 and Rar1, others require only one of the two. A human orthologue of Rar1 has been identified and named Chp1 (CHORD-containing protein) (19). Chp1 is ubiquitously expressed and also interacts with HSP90 (20).…”

Dynamic Nucleotide-dependent Interactions of Cysteine- and Histidine-rich Domain (CHORD)-containing Hsp90 Cochaperones Chp-1 and Melusin with Cochaperones PP5 and Sgt1

“…However, the roles for Chp-1 and melusin, the two mammalian CHORD-containing homologs of Rar1, in innate immunity have not yet been clarified. Chp-1 and melusin contain the additional C-terminal CS domain as well as the two conserved CHORDs (18). Both Chp-1 and melusin interact with Hsp90, suggesting their potential roles as Hsp90 cochap-* This work was supported by Priority Research Centers Program Grant 2011-0031388 from the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology.…”