The R2TP complex: Discovery and functions

• Published in: Biochimica et biophysica acta 2012-01, Vol.1823 (1), p.101-107
• Main Authors: Kakihara, Yoshito, Houry, Walid A.
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphatases - chemistry; Adenosine Triphosphatases - metabolism; Animals; Apoptosis; Complex assembly; DNA Helicases - chemistry; DNA Helicases - metabolism; Dyneins - metabolism; Humans; Molecular Chaperones - chemistry; Molecular Chaperones - metabolism; Multiprotein Complexes - metabolism; Nuclear Proteins - chemistry; Nuclear Proteins - metabolism; Phosphatidylinositol 3-Kinases - metabolism; Pih1; Protein Multimerization; Protein Structure, Quaternary; R2TP; Ribonucleoproteins, Small Nucleolar - biosynthesis; RNA Polymerase II - metabolism; Rvb1; Rvb2; Saccharomyces cerevisiae Proteins - chemistry; Saccharomyces cerevisiae Proteins - metabolism; Signal Transduction; Tah1; Transcription Factors - chemistry; Transcription Factors - metabolism
• ISSN: 0167-4889; 0006-3002; 1879-2596
• DOI: 10.1016/j.bbamcr.2011.08.016

The two closely related AAA+family ATPases Rvb1 and Rvb2 are part of several critical multiprotein complexes, and, thus, are involved in a wide range of cellular processes including chromatin remodelling, telomerase assembly, and snoRNP biogenesis. It was found that Rvb1 and Rvb2 form a tight functional complex with Pih1 (Protein interacting with Hsp90) and Tah1 (TPR-containing protein associated with Hsp90), which are two Hsp90 interactors. We named the complex R2TP. The complex was originally isolated from Saccharomyces cerevisiae and was, subsequently, identified in mammalian cells. R2TP was found to be required for box C/D snoRNP biogenesis in yeast and mammalian cells. More recently, several studies revealed that the complex is also involved in multiple biological processes including apoptosis, phosphatidylinositol-3 kinase-related protein kinase (PIKK) signalling, and RNA polymerase II assembly. In this review, we describe the discovery of the complex and discuss the emerging critical roles that R2TP plays in distinct cellular processes. This article is part of a Special Issue entitled: AAA ATPases: structure and function. ► The R2TP (Rvb1-Rvb2-Tah1-Pih1) complex was identified in 2005 as an Hsp90 associated complex. ► The R2TP complex is conserved from yeast to higher eukaryotes. ► The complex is involved in box C/D snoRNP biogenesis. ► The complex is required for phosphatidylinositol-3 kinase-related protein kinase (PIKK) signalling. ► R2TP is involved in RNA polymerase II assembly.