GAT1/YFL021W Summary

GAT1 BASIC INFORMATION

Standard Name	GAT1
Systematic Name	YFL021W
Alias	NIL1 , MEP80
Feature Type	ORF, Verified
Description	Transcriptional activator of genes involved in nitrogen catabolite repression; contains a GATA-1-type zinc finger DNA-binding motif; activity and localization regulated by nitrogen limitation and Ure2p (1, 2 and see Summary Paragraph)

GO Annotations	All GAT1 GO evidence and references
	View Computational GO annotations for GAT1
Molecular Function
Manually curated	specific RNA polymerase II transcription factor activity (IDA) transcription activator activity (IDA)
High-throughput	sequence-specific DNA binding (IDA)
Biological Process
Manually curated	positive regulation of transcription (IDA) regulation of nitrogen utilization (IMP) transcription initiation from RNA polymerase II promoter (IDA)
Cellular Component
Manually curated	cytosol (IDA) nucleus (IDA)

Regulatory Role
Binding motifs	GAT1 Transcription Factor Binding Sites and References
	AGATAAG GATAA
Regulatory modules	predicted: stressResponse ( 565 , 517 , 463 , 433 , 409 )

Mutant Phenotype	All GAT1 Phenotype details and references
Classical genetics
null	resistance to rapamycin: increased
Large-scale survey
null	resistance to rapamycin: increased resistance to wortmannin: normal viable

Interactions	GAT1 All interactions details and references
	23 total interaction(s) for 15 unique genes/features.
Physical Interactions	Affinity Capture-MS: 2 Affinity Capture-RNA: 1 PCA: 1 Two-hybrid: 1
Genetic Interactions	Dosage Rescue: 6 Phenotypic Enhancement: 7 Phenotypic Suppression: 1 Synthetic Growth Defect: 3 Synthetic Rescue: 1

Sequence Information

ChrVI:95964 to 97496 | |

Last Update

Coordinates: 1996-07-31 | Sequence: 1996-07-31

Subfeature details

	Relative Coordinates	Chromosomal Coordinates	Most Recent Updates
	Relative Coordinates	Chromosomal Coordinates	Coordinates	Sequence
CDS	1..1533	95964..97496	1996-07-31	1996-07-31

External Links	All Associated Seq \| Entrez Gene \| Entrez RefSeq Protein \| MIPS \| UniProtKB

Primary SGDID	S000001873

GAT1 RESOURCES

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SGD ORF map	GBrowse

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Expression Summary

ADDITIONAL INFORMATION for GAT1

NOMENCLATURE CONFLICT NOTE

Name	Relevance	Description
GPT2	Nomenclature conflict	Both GAT1/YFL021W and GPT2/YKR067W have been referred to as GAT1.

SUMMARY PARAGRAPH for GAT1

GAT1 encodes a transcriptional activator that is involved in the positive regulation of genes subject to nitrogen catabolite repression (NCR) (3). Gat1p and Gln3p are both required for activation of NCR-sensitive genes, but the degree to which they influence the expression of a given gene is dependent on the individual gene as well as the nature and quality of the nitrogen source available in the media (4, 5, 6). As determined by sequence homology to Gln3p, Gat1p contains a zinc finger binding domain that binds to the sequence 5-GATAAG-3 in the UAS_NTR found in the promoters of many genes involved in nitrogen utilization (6, 7). Some of the genes under Gat1p regulation include the general amino acid permease gene GAP1, the glutamine synthetase gene GLN1 (6), and CAR1, ASP3, PUT1, and PUT2, which encode enzymes involved in the degradation of arginine, asparagine, and proline respectively (8, 9, 4).

Both the synthesis and the activity of Gat1p are regulated by the quality of environmental nitrogen. When cells are grown on nitrogen-poor media, GAT1 transcription is upregulated by Gln3p (5). Under nitrogen-rich conditions, downregulation of GAT1 transcription is mediated by the repressor Dal80p (5). Ssy1p, a component of the SPS sensor of extracellular amino acids, is also involved in regulating GAT1 expression (10).

When optimal nitrogen sources are available, pre-existing Gat1p is phosphorylated by the TOR kinases Tor1p and Tor2p (11). The phosphorylated form of Gat1p is bound by the regulatory protein Ure2p, which sequesters it in the cytosol, preventing transcription of NCR-sensitive genes (12). In contrast, when nitrogen is limiting, Gat1p is dephosphorylated by the phosphatase Sit4p, subsequently enters the nucleus, and interacts with the transcriptional co-activator Hfi1p to upregulate the expression of NCR-sensitive genes (11, 12, 13). There is also evidence to indicate that activation of Gat1p is dependent on the kinases Arg82p and Kcs1p (14) and antagonized by the transcription factor Gzf3p (15).

Last updated: 2005-10-11

REFERENCES CITED ON THIS PAGE [View Complete Literature Guide for GAT1]

1)	Kuruvilla FG, et al. (2001) Carbon- and nitrogen-quality signaling to translation are mediated by distinct GATA-type transcription factors. Proc Natl Acad Sci U S A 98(13):7283-8
2)	Cooper TG (2002) Transmitting the signal of excess nitrogen in Saccharomyces cerevisiae from the Tor proteins to the GATA factors: connecting the dots. FEMS Microbiol Rev 26(3):223-38
3)	Coffman JA, et al. (1995) Genetic evidence for Gln3p-independent, nitrogen catabolite repression-sensitive gene expression in Saccharomyces cerevisiae. J Bacteriol 177(23):6910-8
4)	Saxena D, et al. (2003) Rapamycin treatment results in GATA factor-independent hyperphosphorylation of the proline utilization pathway activator in Saccharomyces cerevisiae. Eukaryot Cell 2(3):552-9
5)	Coffman JA, et al. (1996) Gat1p, a GATA family protein whose production is sensitive to nitrogen catabolite repression, participates in transcriptional activation of nitrogen-catabolic genes in Saccharomyces cerevisiae. Mol Cell Biol 16(3):847-58
6)	Stanbrough M, et al. (1995) Role of the GATA factors Gln3p and Nil1p of Saccharomyces cerevisiae in the expression of nitrogen-regulated genes. Proc Natl Acad Sci U S A 92(21):9450-4
7)	Stanbrough M and Magasanik B (1996) Two transcription factors, Gln3p and Nil1p, use the same GATAAG sites to activate the expression of GAP1 of Saccharomyces cerevisiae. J Bacteriol 178(8):2465-8
8)	Smart WC, et al. (1996) Combinatorial regulation of the Saccharomyces cerevisiae CAR1 (arginase) promoter in response to multiple environmental signals. Mol Cell Biol 16(10):5876-87
9)	Oliveira EM, et al. (2003) The role of the GATA factors Gln3p, Nil1p, Dal80p and the Ure2p on ASP3 regulation in Saccharomyces cerevisiae. Yeast 20(1):31-7
10)	Forsberg H, et al. (2001) The role of the yeast plasma membrane SPS nutrient sensor in the metabolic response to extracellular amino acids. Mol Microbiol 42(1):215-28
11)	Beck T and Hall MN (1999) The TOR signalling pathway controls nuclear localization of nutrient-regulated transcription factors. Nature 402(6762):689-92
12)	Cunningham TS, et al. (2000) Nitrogen catabolite repression of DAL80 expression depends on the relative levels of Gat1p and Ure2p production in Saccharomyces cerevisiae. J Biol Chem 275(19):14408-14
13)	Soussi-Boudekou S and Andre B (1999) A co-activator of nitrogen-regulated transcription in Saccharomyces cerevisiae. Mol Microbiol 31(3):753-62
14)	El Alami M, et al. (2003) Arg82p is a bifunctional protein whose inositol polyphosphate kinase activity is essential for nitrogen and PHO gene expression but not for Mcm1p chaperoning in yeast. Mol Microbiol 49(2):457-68
15)	Rowen DW, et al. (1997) Role of GATA factor Nil2p in nitrogen regulation of gene expression in Saccharomyces cerevisiae. J Bacteriol 179(11):3761-6

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