Biomaterial Database

Rap1 protein regulates telomere turnover in yeast. 1998

A Krauskopf, and E H Blackburn

Department of Microbiology and Immunology, University of California, San Francisco, CA 94143-0414, USA.

Telomere length is maintained through a dynamic balance between addition and loss of the terminal telomeric DNA. Normal telomere length regulation requires telomerase as well as a telomeric protein-DNA complex. Previous work has provided evidence that in the budding yeasts Kluyveromyces lactis and Saccharomyces cerevisiae, the telomeric double-stranded DNA binding protein Rap1p negatively regulates telomere length, in part by nucleating, by its C-terminal tail, a higher-order DNA binding protein complex that presumably limits access of telomerase to the chromosome end. Here we show that in K. lactis, truncating the Rap1p C-terminal tail (Rap1p-DeltaC mutant) accelerates telomeric repeat turnover in the distal region of the telomere. In addition, combining the rap1-DeltaC mutation with a telomerase template mutation (ter1-kpn), which directs the addition of mutated telomeric DNA repeats to telomeres, synergistically caused an immediate loss of telomere length regulation. Capping of the unregulated telomeres of these double mutants with functionally wild-type repeats restored telomere length control. We propose that the rate of terminal telomere turnover is controlled by Rap1p specifically through its interactions with the most distal telomeric repeats.

UI	MeSH Term	Description	Entries
D007716	Kluyveromyces	An ascomycetous yeast of the fungal family Saccharomycetaceae, order SACCHAROMYCETALES.	Kluyveromyce
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D004268	DNA-Binding Proteins	Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.	DNA Helix Destabilizing Proteins,DNA-Binding Protein,Single-Stranded DNA Binding Proteins,DNA Binding Protein,DNA Single-Stranded Binding Protein,SS DNA BP,Single-Stranded DNA-Binding Protein,Binding Protein, DNA,DNA Binding Proteins,DNA Single Stranded Binding Protein,DNA-Binding Protein, Single-Stranded,Protein, DNA-Binding,Single Stranded DNA Binding Protein,Single Stranded DNA Binding Proteins
D004271	DNA, Fungal	Deoxyribonucleic acid that makes up the genetic material of fungi.	Fungal DNA
D000089804	Shelterin Complex	A TELOMERE cap complex consisting of telomere-specific proteins in association with telomeric DNA such as telomeric dsDNA-sDNA junction. They are involved in the protection of chromosome ends and TELOMERASE regulation and play a role in CELLULAR SENESCENCE and ageing-related pathology. In general it consists of six mostly TELOMERE-BINDING PROTEINS (POT1, RAP1, TIN2, TPP1, TRF1, and TRF2).	CST Complex,Ctc1-Stn1-Ten1 Complex,POT1-TPP1 Shelterin Complex,Telomere Cap Complex,Telomere POT1-TPP1 Complex,Telomeric Capping Complex,Telomeric Stn1-Ten1 Capping Complex,Telosome,Capping Complex, Telomeric,Complex, CST,Complex, Ctc1-Stn1-Ten1,Complex, POT1-TPP1 Shelterin,Complex, Shelterin,Complex, Telomere POT1-TPP1,Complex, Telomeric Capping,Ctc1 Stn1 Ten1 Complex,POT1 TPP1 Shelterin Complex,POT1-TPP1 Complex, Telomere,Shelterin Complex, POT1-TPP1,Telomere POT1 TPP1 Complex,Telomeric Stn1 Ten1 Capping Complex,Telosomes
D014157	Transcription Factors	Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.	Transcription Factor,Factor, Transcription,Factors, Transcription
D016615	Telomere	A terminal section of a chromosome which has a specialized structure and which is involved in chromosomal replication and stability. Its length is believed to be a few hundred base pairs.	Telomeres
D029701	Saccharomyces cerevisiae Proteins	Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.	Baker's Yeast Proteins,S cerevisiae Proteins
D034501	Telomere-Binding Proteins	Proteins that specifically bind to TELOMERES. Proteins in this class include those that perform functions such as telomere capping, telomere maintenance and telomere stabilization.	Telomere-Binding Protein,Double-Stranded Telomere-Binding Proteins,Double-Stranded Telomeric Binding Protein,Single-Stranded Telomere-Binding Protein,Single-Stranded Telomere-Binding Proteins,Telomer-Binding Protein, alpha-Subunit,Telomer-Binding Protein, beta-Subunit,Telomere End-Binding Protein (TEBP),Telomere Repeat Binding Factor,Telomere Repeat Binding Factors,Telomere Repeat Binding Proteins,Telomere-Binding Proteins, Double Stranded,Telomere-Binding Proteins, Single-Stranded,alpha-Telomere-Binding Protein,beta-Telomere-Binding Protein,Double Stranded Telomere Binding Proteins,Double Stranded Telomeric Binding Protein,Protein, Telomere-Binding,Single Stranded Telomere Binding Protein,Single Stranded Telomere Binding Proteins,Telomer Binding Protein, alpha Subunit,Telomer Binding Protein, beta Subunit,Telomere Binding Protein,Telomere Binding Proteins,Telomere Binding Proteins, Double Stranded,Telomere Binding Proteins, Single Stranded,Telomere-Binding Protein, Single-Stranded,Telomere-Binding Proteins, Double-Stranded,alpha Telomere Binding Protein,alpha-Subunit Telomer-Binding Protein,beta Telomere Binding Protein,beta-Subunit Telomer-Binding Protein