Functional requirement of p23 and Hsp90 in telomerase complexes.

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.

[1]  D. Toft,et al.  The Assembly of Progesterone Receptor-hsp90 Complexes Using Purified Proteins* , 1998, The Journal of Biological Chemistry.

[2]  D. Toft.  Recent Advances in the Study of hsp90 Structure and Mechanism of Action , 1998, Trends in Endocrinology & Metabolism.

[3]  M. Galigniana,et al.  The Role of DnaJ-like Proteins in Glucocorticoid Receptor·hsp90 Heterocomplex Assembly by the Reconstituted hsp90·p60·hsp70 Foldosome Complex* , 1998, The Journal of Biological Chemistry.

[4]  R. Rimerman,et al.  Analysis of FKBP51/FKBP52 chimeras and mutants for Hsp90 binding and association with progesterone receptor complexes. , 1998, Molecular endocrinology.

[5]  S. Benchimol,et al.  Reconstitution of telomerase activity in normal human cells leads to elongation of telomeres and extended replicative life span , 1998, Current Biology.

[6]  C. Harley,et al.  Extension of life-span by introduction of telomerase into normal human cells. , 1998, Science.

[7]  J. Shay,et al.  Normal human chromosomes have long G-rich telomeric overhangs at one end. , 1997, Genes & development.

[8]  J. Shay,et al.  Lack of cell cycle regulation of telomerase activity in human cells. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[9]  Timothy A. J. Haystead,et al.  The Amino-terminal Domain of Heat Shock Protein 90 (hsp90) That Binds Geldanamycin Is an ATP/ADP Switch Domain That Regulates hsp90 Conformation* , 1997, The Journal of Biological Chemistry.

[10]  W. Pratt,et al.  Folding of the Glucocorticoid Receptor by the Heat Shock Protein (hsp) 90-based Chaperone Machinery , 1997, The Journal of Biological Chemistry.

[11]  R. Weinberg,et al.  hEST2, the Putative Human Telomerase Catalytic Subunit Gene, Is Up-Regulated in Tumor Cells and during Immortalization , 1997, Cell.

[12]  C B Harley,et al.  Telomerase catalytic subunit homologs from fission yeast and human. , 1997, Science.

[13]  L. Pearl,et al.  Identification and Structural Characterization of the ATP/ADP-Binding Site in the Hsp90 Molecular Chaperone , 1997, Cell.

[14]  W. Pratt,et al.  Steroid receptor interactions with heat shock protein and immunophilin chaperones. , 1997, Endocrine reviews.

[15]  W. Pratt,et al.  Folding of the Glucocorticoid Receptor by the Reconstituted hsp90-based Chaperone Machinery , 1997, The Journal of Biological Chemistry.

[16]  T R Hughes,et al.  Reverse transcriptase motifs in the catalytic subunit of telomerase. , 1997, Science.

[17]  E. Alnemri,et al.  Nucleotides and Two Functional States of hsp90* , 1997, The Journal of Biological Chemistry.

[18]  A. Matsuura,et al.  TLP1: A Gene Encoding a Protein Component of Mammalian Telomerase Is a Novel Member of WD Repeats Family , 1997, Cell.

[19]  Lea Harrington,et al.  A Mammalian Telomerase-Associated Protein , 1997, Science.

[20]  C. Seeger,et al.  Hepadnavirus assembly and reverse transcription require a multi‐component chaperone complex which is incorporated into nucleocapsids , 1997, The EMBO journal.

[21]  Gregg B. Morin,et al.  Reconstitution of human telomerase with the template RNA component hTR and the catalytic protein subunit hTRT , 1997, Nature Genetics.

[22]  R. Morimoto,et al.  Molecular Chaperone Machines: Chaperone Activities of the Cyclophilin Cyp-40 and the Steroid Aporeceptor-Associated Protein p23 , 1996, Science.

[23]  E. Alnemri,et al.  Cooperative action of Hsp70, Hsp90, and DnaJ proteins in protein renaturation. , 1996, Biochemistry.

[24]  J. Shay,et al.  Telomerase activity in human intestine. , 1996, International journal of oncology.

[25]  J. Shay,et al.  Regulation of telomerase activity in immortal cell lines , 1996, Molecular and cellular biology.

[26]  J. Shay,et al.  Detection of telomerase activity in malignant and nonmalignant skin conditions. , 1996, The Journal of investigative dermatology.

[27]  C. Seeger,et al.  Hsp90 is required for the activity of a hepatitis B virus reverse transcriptase. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[28]  J. Shay,et al.  Telomerase activity in human germline and embryonic tissues and cells. , 1996, Developmental genetics.

[29]  D. Broccoli,et al.  Telomerase activity in normal and malignant hematopoietic cells. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[30]  et al.,et al.  The RNA component of human telomerase , 1995, Science.

[31]  W. Pratt,et al.  The 23-kDa Acidic Protein in Reticulocyte Lysate Is the Weakly Bound Component of the hsp Foldosome That Is Required for Assembly of the Glucocorticoid Receptor into a Functional Heterocomplex with hsp90 (*) , 1995, The Journal of Biological Chemistry.

[32]  J. Johnson,et al.  Binding of p23 and hsp90 during assembly with the progesterone receptor. , 1995, Molecular endocrinology.

[33]  F. Spencer.  The telomere. , 1995, Science.

[34]  C B Harley,et al.  Specific association of human telomerase activity with immortal cells and cancer. , 1994, Science.

[35]  J. Johnson,et al.  A novel chaperone complex for steroid receptors involving heat shock proteins, immunophilins, and p23. , 1994, The Journal of biological chemistry.

[36]  R. Hurst,et al.  ATP-dependent chaperoning activity of reticulocyte lysate. , 1994, The Journal of biological chemistry.

[37]  J. Johnson,et al.  Characterization of a novel 23-kilodalton protein of unactive progesterone receptor complexes , 1994, Molecular and cellular biology.

[38]  Jonathan A. Cooper,et al.  Mammalian Ras interacts directly with the serine/threonine kinase raf , 1993, Cell.

[39]  C B Harley,et al.  Loss of telomeric DNA during aging of normal and trisomy 21 human lymphocytes. , 1993, American journal of human genetics.

[40]  C B Harley,et al.  Telomere length predicts replicative capacity of human fibroblasts. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[41]  P. Casey,et al.  Farnesylation of YDJ1p is required for function at elevated growth temperatures in Saccharomyces cerevisiae. , 1992, The Journal of biological chemistry.

[42]  C B Harley,et al.  Telomere loss: mitotic clock or genetic time bomb? , 1991, Mutation research.

[43]  H. Cooke,et al.  In vivo loss of telomeric repeats with age in humans. , 1991, Mutation research.

[44]  Robin C. Allshire,et al.  Telomere reduction in human colorectal carcinoma and with ageing , 1990, Nature.

[45]  H. Land,et al.  Advanced mammalian gene transfer: high titre retroviral vectors with multiple drug selection markers and a complementary helper-free packaging cell line. , 1990, Nucleic acids research.

[46]  C. Harley,et al.  Telomeres shorten during ageing of human fibroblasts , 1990, Nature.

[47]  G. Morin.  The human telomere terminal transferase enzyme is a ribonucleoprotein that synthesizes TTAGGG repeats , 1989, Cell.

[48]  S. Fields,et al.  A novel genetic system to detect protein–protein interactions , 1989, Nature.

[49]  E. Blackburn,et al.  A telomeric sequence in the RNA of Tetrahymena telomerase required for telomere repeat synthesis , 1989, Nature.

[50]  L. S. Cram,et al.  A highly conserved repetitive DNA sequence, (TTAGGG)n, present at the telomeres of human chromosomes. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[51]  E. Schneider,et al.  The relationship between in vitro cellular aging and in vivo human age. , 1976, Proceedings of the National Academy of Sciences of the United States of America.

[52]  A M Olovnikov,et al.  A theory of marginotomy. The incomplete copying of template margin in enzymic synthesis of polynucleotides and biological significance of the phenomenon. , 1973, Journal of theoretical biology.

[53]  C. Epstein,et al.  Replicative life-span of cultivated human cells. Effects of donor's age, tissue, and genotype. , 1970, Laboratory investigation; a journal of technical methods and pathology.