Disease relevance of POT1

• The non-conventional yeast Arxula adeninivorans was equipped with the genes phbA, phbB and phbC of the polyhydroxyalkanoate (PHA) biosynthetic pathway of Ralstonia eutropha, which encode beta-ketothiolase, NADPH-linked acetoacetyl-CoA reductase and PHA synthase, respectively [1].

High impact information on POT1

• Proteins with high affinity for the structure at chromosome ends, binding the G-rich, 3' single-stranded overhang at telomeres include Pot1 in humans and fission yeast, TEBP in Oxytricha nova and Cdc13 in budding yeast [2].
• A 304-amino-acid stretch comprising 11 of the 12 catalytic subdomains of Stk2p is approximately 83% homologous to the putative Pot1p/Kkt8p (Stk1p) protein kinase, a recently described activator of low-affinity spermine uptake in yeast [3].
• The upstream region of the FOX3 gene encoding peroxisomal 3-oxoacyl-coenzyme A thiolase in Saccharomyces cerevisiae contains ABF1- and replication protein A-binding sites that participate in its regulation by glucose repression [4].
• Expression of the FOX3 gene, which encodes yeast peroxisomal 3-oxoacyl-coenzyme A thiolase, can be induced by oleate and repressed by glucose [4].
• Mutants with no acyl-CoA oxidase activity could not reconsume gamma-decalactone, and mutants with a disruption of pox3, which encodes the short-chain acyl-CoA oxidase, reconsumed it more slowly [5].

Biological context of POT1

• We studied the consequences of adr1 and snf1 mutations on POT1 gene expression in different growth conditions [6].
• With this objective in mind, we analyzed a chromatin region of the yeast Chromosome (Chr) IX, in which there are two closely packed open reading frames (ORFs), POT1 and YIL161w [7].
• We have studied the case of two convergent closely packed ORFs (56 bp of separation) in chromosome IX of Saccharomyces cerevisiae. mRNAs from POT1 and YIL161w overlap by up to 115 nt [8].
• One of the isolated clones contained, in addition to the POT1 coding sequence, 784 bp of the corresponding 5' flanking region [9].
• Using a Yarrowia lipolytica genomic library, several overlapping clones of the peroxisomal 3-oxoacyl-CoA-thiolase gene, POT1, were isolated [9].

Associations of POT1 with chemical compounds

• In a ras2 mutant, which has low PKA activity, glucose repression is not alleviated but in non-repressing conditions POT1 regulation is perturbed and expression prematurely increases during exponential phase [10].
• This inability to grow in the presence of oleate suggests both the catabolic function of POT1 and the absence of additional catabolic thiolases in Y. lipolytica [9].
• The deduced amino acid sequence of the PTK2 gene product was 38% identical and 55% similar with that of the PTK1 (POT1) gene product, a putative serine/threonine protein kinase, which was found to enhance spermine uptake of the same mutant [11].
• The nucleotide sequence of the POT1 gene indicated that it encodes a putative serine/threonine protein kinase and is located on chromosome XI [12].

Other interactions of POT1

• ADR1 and SNF1 mediate different mechanisms in transcriptional regulation of yeast POT1 gene [6].
• At least for the peroxisomal thiolase gene (POT1) there is a third regulatory mechanism, mediated by the transcription factor Adr1p, which is responsible for the high-level expression of the gene in stationary phase [10].
• PKA exerts a negative control: the high, unregulated PKA activity in a bcy1 mutant maintains POT1 transcription at the repressed level [10].

Analytical, diagnostic and therapeutic context of POT1

• These alterations of telomeric DNA were accompanied by alterations of telomeric chromatin structures as revealed by quantitative chromatin immunoprecipitation and immunofluorescence analyses of TRF1 and POT1 [13].

References