Functional requirement of p23 and Hsp90 in telomerase complexes
AUTOR(ES)
Holt, Shawn E.
FONTE
Cold Spring Harbor Laboratory Press
RESUMO
Most normal human diploid cells have no detectable telomerase; however, expression of the catalytic subunit of telomerase is sufficient to induce telomerase activity and, in many cases, will bypass normal senescence. We and others have previously demonstrated in vitro assembly of active telomerase by combining the purified RNA component with the reverse transcriptase catalytic component synthesized in rabbit reticulocyte extract. Here we show that assembly of active telomerase from in vitro-synthesized components requires the contribution of proteins present in reticulocyte extracts. We have identified the molecular chaperones p23 and Hsp90 as proteins that bind to the catalytic subunit of telomerase. Blockade of this interaction inhibits assembly of active telomerase in vitro. Also, a significant fraction of active telomerase from cell extracts is associated with p23 and Hsp90. Consistent with in vitro results, inhibition of Hsp90 function in cells blocks assembly of active telomerase. To our knowledge, p23 and Hsp90 are the first telomerase-associated proteins demonstrated to contribute to telomerase activity.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=316592Documentos Relacionados
- A Truncated Form of p23 Down-regulates Telomerase Activity via Disruption of Hsp90 Function*
- Estudos estruturais e funcionais da Hsp90 de Leishmania braziliensis e suas co-chaperonas p23
- Polypeptide release by Hsp90 involves ATP hydrolysis and is enhanced by the co-chaperone p23
- SBA1 Encodes a Yeast Hsp90 Cochaperone That Is Homologous to Vertebrate p23 Proteins
- Differential interactions of p23 and the TPR-containing proteins Hop, Cyp40, FKBP52 and FKBP51 with Hsp90 mutants