High impact information on POL12

• Unlike many POL1 and POL12 mutations, which also cause telomere elongation, the pol12-216 mutation described here does not lead to either reduced Pol1 function, increased telomeric single-stranded DNA, or a reduction in telomeric gene silencing [1].
• We propose that Pol12, together with Stn1, plays a key role in linking telomerase action with the completion of lagging strand synthesis, and in a regulatory step required for telomere capping [1].
• Pol12, the B subunit of DNA polymerase alpha, functions in both telomere capping and length regulation [1].
• Here we describe a genetic screen in yeast for mutants with relaxed telomere length regulation, and the identification of Pol12, the B subunit of the DNA polymerase alpha (Pol1)-primase complex, as a new factor involved in this process [1].
• The function of the B subunit of the complex is unknown, but the Saccharomyces cerevisiae POL12 gene, which encodes this protein, is essential for cell viability [2].

Biological context of POL12

• Moreover, reciprocal shift experiments indicate that the POL12 gene product plays an essential role at the early stage of chromosomal DNA replication, before the hydroxyurea-sensitive step [2].
• We have produced different pol12 alleles by in vitro mutagenesis of the cloned gene [2].
• Pri2 and Pol12 took on a beaded appearance at the G(1)-S transition and later in the cell cycle were enriched in the nuclear envelope [3].
• Sequence analysis reveals four new open reading frames longer than 300 bp: YBL0415 (309 bp), YBL0416 (4539 bp), YBL0417 (1035 bp) and YBL0414 (2115 bp), which extends into the neighbouring 5.2 kb BamHI fragment [4].

Associations of POL12 with chemical compounds

• The in vivo analysis of our 18 pol12 alleles indicates that the conserved carboxy-terminal two-thirds of the protein contains regions that are essential for cell viability, while the more divergent NH2-terminal portion is partially dispensable [2].

Other interactions of POL12

• Moreover, overexpressed Cdc17 that is normally subject to rapid degradation is stabilized by Mcm10 co-overexpression but not by co-overexpression of the B-subunit of pol-alpha, Pol12 [5].

References