KTI12/YKL110C Summary Help

Standard Name KTI12 1
Systematic Name YKL110C
Alias TOT4 2
Feature Type ORF, Verified
Description Protein that plays a role in modification of tRNA wobble nucleosides; protein plays role in tRNA wobble nucleoside modification with Elongator complex; involved in sensitivity to G1 arrest induced by zymocin; interacts with chromatin throughout the genome; also interacts with Cdc19p (1, 3, 4, 5 and see Summary Paragraph)
Name Description Kluveromyces lactis Toxin Insensitive 6
Chromosomal Location
ChrXI:229880 to 228939 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All KTI12 GO evidence and references
  View Computational GO annotations for KTI12
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 10 genes
Classical genetics
Large-scale survey
137 total interaction(s) for 105 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 1
  • Affinity Capture-RNA: 2
  • Affinity Capture-Western: 26
  • Co-fractionation: 3
  • Co-purification: 1
  • Two-hybrid: 2

Genetic Interactions
  • Dosage Rescue: 1
  • Negative Genetic: 80
  • Positive Genetic: 4
  • Synthetic Growth Defect: 15
  • Synthetic Lethality: 2

Expression Summary
Length (a.a.) 313
Molecular Weight (Da) 35,322
Isoelectric Point (pI) 7.98
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXI:229880 to 228939 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..942 229880..228939 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000001593

KTI12 encodes a protein that associates with Elongator complex, a six-subunit histone acetytransferase complex that functions with the elongating form of RNA polymerase II during transcription (5, 7, 3). KTI12 was first identified in a screen for mutants insensitive to the Kluyveromyces lactis toxin zymocin, which causes cell cycle arrest in G1 phase (1, 2). Both mutation and overexpression of KTI12 were found to confer toxin resistance, in contrast to the other genes identified in the screen, whose overexpression did not confer resistance (1, 8). Loss of Kti12p function also results in slow growth at 30 degrees and temperature sensitivity above 38 degrees, and sensitivity to the cell wall poison Calcofluor White, the purine analog caffeine, and the nucleotide biosynthesis inhibitor 6-azauracil (6-AU; 2).

The pleiotropic phenotypes exhibited by kti12 mutants may be due in part to a requirement for Elongator complex, Kti11p, Kti12p, and Ats1p in synthesis of the 5-methoxycarbonylmethyl (mcm5) and 5-carbamoylmethyl (ncm5) groups that are added to uridine nucleosides located at the wobble position of tRNA during tRNA maturation (4). Absence of these modifications on tRNA affects decoding of mRNA. Kti12p has also been shown to interact with pyruvate kinase, Cdc19p, suggesting an involvement in regulating or coordinating carbon source metabolism and growth (3).

Biochemical and genetic data point to an important functional interaction between Kti12p and Elongator complex. A salt-labile physical interaction has been demonstrated (5). In addition, Kti12p interacts with the form of RNA polymerase II that is hyperphosphorylated on serine 5 of the C-terminal domain (CTD) repeats (3, 7). However, as deletion of Kti12p does not affect the structural integrity of the Elongator complex, and Kti12p does not copurify with Elongator, it is unlikely that Kti12p is a structural component of the complex (8, 5). Genetic experiments indicate that Kti12p is required for normal histone acetyltransferase activity of Elongator in vivo (5). Interactions between Kti12p and DNA have been reported to occur primarily in the promoter region rather than in coding sequences (3), while other work indicates that Kti12p is associated with chromatin throughout the genome (5). Kti12p has been proposed to play a regulatory role in Elongator function (8), an hypothesis supported by the finding that Kti12p antagonizes the action of the Sit4p phosphatase in dephosphorylation of the Iki3p subunit of Elongator (9).

Last updated: 2006-10-10 Contact SGD

References cited on this page View Complete Literature Guide for KTI12
1) Butler AR, et al.  (1994) Two Saccharomyces cerevisiae genes which control sensitivity to G1 arrest induced by Kluyveromyces lactis toxin. Mol Cell Biol 14(9):6306-16
2) Frohloff F, et al.  (2001) Saccharomyces cerevisiae Elongator mutations confer resistance to the Kluyveromyces lactis zymocin. EMBO J 20(8):1993-2003
3) Fichtner L, et al.  (2002) Protein interactions within Saccharomyces cerevisiae Elongator, a complex essential for Kluyveromyces lactis zymocicity. Mol Microbiol 45(3):817-26
4) Huang B, et al.  (2005) An early step in wobble uridine tRNA modification requires the Elongator complex. RNA 11(4):424-36
5) Petrakis TG, et al.  (2005) Physical and functional interaction between Elongator and the chromatin-associated Kti12 protein. J Biol Chem 280(20):19454-60
6) Butler AR, et al.  (1991) Intracellular expression of Kluyveromyces lactis toxin gamma subunit mimics treatment with exogenous toxin and distinguishes two classes of toxin-resistant mutant. Yeast 7(6):617-25
7) Frohloff F, et al.  (2003) Subunit communications crucial for the functional integrity of the yeast RNA polymerase II elongator (gamma-toxin target (TOT)) complex. J Biol Chem 278(2):956-61
8) Fichtner L, et al.  (2002) Molecular analysis of KTI12/TOT4, a Saccharomyces cerevisiae gene required for Kluyveromyces lactis zymocin action. Mol Microbiol 43(3):783-91
9) Jablonowski D, et al.  (2004) The yeast elongator histone acetylase requires Sit4-dependent dephosphorylation for toxin-target capacity. Mol Biol Cell 15(3):1459-69