SPT14/YPL175W Summary Help

Standard Name SPT14 1
Systematic Name YPL175W
Alias CWH6 , GPI3 2
Feature Type ORF, Verified
Description UDP-glycosyltransferase subunit of the GPI-GnT complex; UDP-GlcNAc-binding and catalytic subunit of the enzyme that mediates the first step in glycosylphosphatidylinositol (GPI) biosynthesis, mutations cause defects in transcription and in biogenesis of cell wall proteins (3, 4 and see Summary Paragraph)
Name Description SuPpressor of Ty 1
Chromosomal Location
ChrXVI:218630 to 220088 | ORF Map | GBrowse
Genetic position: -113 cM
Gene Ontology Annotations All SPT14 GO evidence and references
  View Computational GO annotations for SPT14
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 3 genes
Classical genetics
Large-scale survey
reduction of function
72 total interaction(s) for 62 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 3
  • Affinity Capture-Western: 1
  • PCA: 2

Genetic Interactions
  • Dosage Rescue: 1
  • Negative Genetic: 55
  • Positive Genetic: 6
  • Synthetic Growth Defect: 2
  • Synthetic Lethality: 2

Expression Summary
Length (a.a.) 452
Molecular Weight (Da) 51,242
Isoelectric Point (pI) 7.25
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXVI:218630 to 220088 | ORF Map | GBrowse
Genetic position: -113 cM
Last Update Coordinates: 2011-02-03 | Sequence: 2000-07-14
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..17 218630..218646 2011-02-03 2000-07-14
Intron 18..117 218647..218746 2011-02-03 2000-07-14
CDS 118..1459 218747..220088 2011-02-03 2000-07-14
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 SGDIDS000006096

SPT14 is one member of a large class of SPT genes, which were named for their ability to suppress the phenotypes resulting from Ty insertions that disrupted transcription of nearby genes (1, 5). The role Spt14p plays in transcription is likely an indirect one, as it has been found to encode a glycosyl transferase that transfers N-acetylglucosamine from UDP-N-acetylglucosamine to phosphatidyl inositol, the first step of glycosyl phosphatidyl inositol (GPI) biosynthesis (6, 7). This reaction requires the action of at least three gene products in yeast (Gpi1p, Gpi2p, and Spt14p) and human (PIG-C, PIG-H, and PIG-A) (6, 2). Spt14p shows high similarity to the human PIG-A protein, mutations in which are responsible for the disease paroxysmal nocturnal hemoglobinuria (7, 8, 9). Because GPI acts as a membrane anchor for many proteins, spt14 mutants have defects in GPI anchoring, and in the release of cell wall proteins from the endoplasmic reticulum (7, 10).

Last updated: 2000-03-10 Contact SGD

References cited on this page View Complete Literature Guide for SPT14
1) Fassler JS and Winston F  (1988) Isolation and analysis of a novel class of suppressor of Ty insertion mutations in Saccharomyces cerevisiae. Genetics 118(2):203-12
2) Leidich SD, et al.  (1995) Temperature-sensitive yeast GPI anchoring mutants gpi2 and gpi3 are defective in the synthesis of N-acetylglucosaminyl phosphatidylinositol. Cloning of the GPI2 gene. J Biol Chem 270(22):13029-35
3) Vossen JH, et al.  (1995) Identification of SPT14/CWH6 as the yeast homologue of hPIG-A, a gene involved in the biosynthesis of GPI anchors. Biochim Biophys Acta 1243(3):549-51
4) Kostova Z, et al.  (2000) Photoaffinity labelling with P3-(4-azidoanilido)uridine 5'-triphosphate identifies gpi3p as the UDP-GlcNAc-binding subunit of the enzyme that catalyses formation of GlcNAc-phosphatidylinositol, the first glycolipid intermediate in glycosylphosphatidylinositol synthesis. Biochem J 350 Pt 3():815-22
5) Winston F and Sudarsanam P  (1998) The SAGA of Spt proteins and transcriptional analysis in yeast: past, present, and future. Cold Spring Harb Symp Quant Biol 63:553-61
6) Inoue N, et al.  (1996) PIG-C, one of the three human genes involved in the first step of glycosylphosphatidylinositol biosynthesis is a homologue of Saccharomyces cerevisiae GPI2. Biochem Biophys Res Commun 226(1):193-9
7) Schonbachler M, et al.  (1995) The yeast spt14 gene is homologous to the human PIG-A gene and is required for GPI anchor synthesis. EMBO J 14(8):1637-45
8) Kawagoe K, et al.  (1994) Molecular cloning of murine pig-a, a gene for GPI-anchor biosynthesis, and demonstration of interspecies conservation of its structure, function, and genetic locus. Genomics 23(3):566-74
9) Bessler M, et al.  (1994) Genomic organization of the X-linked gene (PIG-A) that is mutated in paroxysmal nocturnal haemoglobinuria and of a related autosomal pseudogene mapped to 12q21. Hum Mol Genet 3(5):751-7
10) Vossen JH, et al.  (1997) Restrictive glycosylphosphatidylinositol anchor synthesis in cwh6/gpi3 yeast cells causes aberrant biogenesis of cell wall proteins. J Bacteriol 179(7):2202-9