YRF1-6/YNL339C Summary Help

Standard Name YRF1-6
Systematic Name YNL339C
Alias YRF1
Feature Type ORF, Verified
Description Helicase encoded by the Y' element of subtelomeric regions; highly expressed in the mutants lacking the telomerase component TLC1; potentially phosphorylated by Cdc28p (1, 2 and see Summary Paragraph)
Chromosomal Location
ChrXIV:6098 to 371 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All YRF1-6 GO evidence and references
  View Computational GO annotations for YRF1-6
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 10 genes
Large-scale survey
12 total interaction(s) for 12 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 2
  • Affinity Capture-RNA: 2
  • Biochemical Activity: 1
  • PCA: 2

Genetic Interactions
  • Phenotypic Enhancement: 2
  • Synthetic Growth Defect: 3

Expression Summary
Length (a.a.) 1,859
Molecular Weight (Da) 211,097
Isoelectric Point (pI) 7.19
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXIV:6098 to 371 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
This feature contains embedded feature(s): YNL339W-A | YNL339W-B
This feature is contained within: TEL14L
This feature is contained within: TEL14L-YP
Last Update Coordinates: 1996-07-31 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..19 6098..6080 1996-07-31 1996-07-31
Intron 20..167 6079..5932 1996-07-31 1996-07-31
CDS 168..5728 5931..371 1996-07-31 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000005283

The YRF1 genes are found in telomeric Y' elements and encode a DNA helicase known as Y'-Help1 (Y'-HELicase Protein 1), which is induced in strains deficient for telomerase activity (1). Native Y' elements do not appear to be expressed in wild-type cells, probably due to the telomeric silencing effect (3). Thus, Y'-Help1 expression from shortened telomeres, in which silencing is no longer effective, seems to indicate the presence of a system for the compensation of telomeric loss by telomerase-independent mechanisms (1). It is proposed that the induction of Y'-Help1 promotes homologous DNA recombination among Y' elements, thereby facilitating their amplification, resulting in the lengthening of telomeric ends and prevention of chromosome loss and cell death. This amplification of Y' elements will further increase the production of Y'-Help1, establishing a positive feedback circuit for telomeric rescue in cells with shortened telomeres (1).

The N-terminal region of Y'-Help1 is composed of motifs conserved in the DEAD/DEAH (or DEXH) subfamily of helicases, and the central region of the protein contains several tandem repeats of the serine-threonine-rich 12-amino acid sequence SXTXATTTXSXX, the number of which varies between the different Y' elements (1). Y'-Help1 also shares regions of homology with the RNA helicase eukaryotic translation initiation factor 4A (Tif1p and Tif2p in S. cerevisiae), as well as the homologous DNA recombination protein RecG of the hyperthermophilic bacterium Aquifex (1).

Last updated: 2006-06-27 Contact SGD

References cited on this page View Complete Literature Guide for YRF1-6
1) Yamada M, et al.  (1998) Y'-Help1, a DNA helicase encoded by the yeast subtelomeric Y' element, is induced in survivors defective for telomerase. J Biol Chem 273(50):33360-6
2) Ubersax JA, et al.  (2003) Targets of the cyclin-dependent kinase Cdk1. Nature 425(6960):859-64
3) Gottschling DE, et al.  (1990) Position effect at S. cerevisiae telomeres: reversible repression of Pol II transcription. Cell 63(4):751-62