POLA1
POLA1 (DNA polymerase alpha 1, catalytic subunit, also known as p180, POLA and NSX) is the catalytic subunit of the DNA polymerase alpha complex. It plays an essential role in the initiation of DNA synthesis during replication. Browse Assay Genie's current range of POLA1 research reagents below, or read on for the biology behind the target.
POLA1 is the catalytic subunit of the DNA polymerase alpha complex, also called the alpha DNA polymerase-primase complex. The complex is composed of POLA1, a regulatory subunit POLA2 and two primase subunits, PRIM1 and PRIM2. During S phase of the cell cycle it is recruited to DNA at replicative forks through direct interactions with MCM10 and WDHD1. The primase subunit initiates DNA synthesis by oligomerising short RNA primers on both the leading and lagging strands. The POLA1 catalytic subunit then extends these primers.
The extended primers are subsequently handed over to polymerase delta and polymerase epsilon, which carry out processive synthesis on the lagging and leading strand respectively. This transfer is needed because polymerase alpha has limited processivity and lacks intrinsic 3' exonuclease activity for proofreading, so it is poorly suited to replicating long stretches of DNA. The enzyme belongs to the DNA polymerase type-B family and is classed by HGNC in the DNA polymerases gene group (EC 2.7.7.7).
UniProt reports POLA1 in the nucleus and in the cytosol. In the cytosol it is responsible for a substantial proportion of the physiological concentration of cytosolic RNA:DNA hybrids, which are necessary to prevent spontaneous activation of type I interferon responses. The POLA1 gene was previously named polymerase (DNA directed), alpha, and carried the symbol NSX, from the earlier name N syndrome (mental retardation, malformations, chromosome breakage). Mouse and rat orthologs are both designated Pola1.
POLA1 extends RNA primers laid down by the primase subunits, making it central to studies of how DNA synthesis begins at replicative forks.
The complex is recruited to forks in S phase via MCM10 and WDHD1, so POLA1 is relevant to replication-fork assembly and S-phase control.
Limited processivity and no 3' exonuclease proofreading mean POLA1 hands off to polymerase delta and epsilon, a model for polymerase switching.
Cytosolic POLA1 contributes to RNA:DNA hybrids that prevent spontaneous type I interferon responses, linking replication enzymes to nucleic-acid sensing.
POLA1 is the catalytic subunit of the DNA polymerase alpha complex and is essential for initiating DNA synthesis. It extends short RNA primers made by the primase subunits before polymerase delta and epsilon take over. In the cytosol it also contributes to RNA:DNA hybrids that restrain type I interferon responses.
POLA1 is also known as p180, POLA and NSX. Earlier names include polymerase (DNA directed), alpha, and polymerase (DNA) alpha 1, catalytic subunit. The NSX symbol derived from N syndrome (mental retardation, malformations, chromosome breakage). Its partner subunit in the complex is POLA2.
Yes. Mouse and rat both carry a Pola1 ortholog of the human gene. The protein belongs to the DNA polymerase type-B family. Check the datasheet of any product for its validated reactivity.
POLA2, the regulatory subunit of the DNA polymerase alpha complex, and other DNA replication targets with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P09884; product specifications from Assay Genie datasheets.