DNApol-alpha180, DNApol-α, DNA polymerase α, DNApol-α180, POLA
Gene model reviewed during 5.47
There is only one protein coding transcript and one polypeptide associated with this gene
Component of the alpha DNA polymerase complex (also known as the alpha DNA polymerase-primase complex) consisting of four subunits: the catalytic subunit PolA1, the regulatory subunit PolA2, and the primase complex subunits Prim1 and Prim2 respectively (PubMed:6773966, PubMed:6403945, PubMed:6409898, PubMed:7592543). PolA1 associates with the DNA primase complex before association with PolA2 (PubMed:6409898). Interacts with Dpit47; the interaction inhibits the activity of the DNA polymerase and occurs only in proliferating cells but not in quiescent cells (PubMed:11493638).
In embryos, a cleaved form of 130 kDa is produced up to cycle 14 and then disappears.
The CysA-type zinc finger is required for PCNA-binding.
The CysB motif binds 1 4Fe-4S cluster and is required for the formation of polymerase complexes.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\PolA1 using the Feature Mapper tool.
PolA1 protein is observed in nuclei of nurse cells and follicle cells. During early stages of embryogenesis, PolA1 protein is mainly nuclear although dispersal occurrs during mitotic phases of the cell cycle.
GBrowse - Visual display of RNA-Seq signalsView Dmel\PolA1 in GBrowse 2
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Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Reducing DNApol-α180 levels by itself des not result in any defects, while reducing DNApol-α180 levels in the absence of mei-41 results in elevated p53-dependent apoptosis, rough eyes and increased genomic instability.
In vitro binding studies of E2f and Dp to the DNApol-α180 promoter region reveals each of the E2f binding sites plays a distinct role as positive or negative element in the regulation of the DNApol-α180 promoter during development.
A specific polyclonal antibody stains interphase nuclei and the surrounding cytoplasmic regions. The protein is present in the embryo as a maternal product. The 130kD proteolytic product is also present in embryos as a maternal product; unlike the 180kD protein this decreases in amount after cycle 10 and is not detectable after cycle 14.
Subunits of DNA polymerase α and δ are purified from embryos and characterised.
Expression pattern and subcellular distribution of the protein during development is studied using antibodies.
DNApol-α180 is negatively regulated by zen protein. This repression is mediated by the DRE (DNA replication-related element) sites in the DNApol-α180 promoter. The amount of Dref is reduced in transfected Kc cells expressing zen, suggesting that zen represses expression of DNA replication-related genes by reducing the amount of Dref.
The properties of the DNA polymerase α enzyme have been studied.
DNApol-α and mus209 products share DRE, an 8bp palindrome required for high expression.
Immunoaffinity-purified DNA polymerase α-primase includes not only the 180kD protein, but also 145, 140 and 130kD proteins, due to proteolytic cleavage of the 180kD protein at F130/S131, T180/S181 and F237/S238.
Embryonic DNA polymerase α complex, isolated by immunological techniques, contains a protein kinase activity. The kinase will phosphorylate His1, but prefers peptides contained in the DNA polymerase α kinase complex.
Mono Q anion exchange chromatography used to resolve DNA polymerase activities in 0-2.5hr embryos. DNApol-δ and DNApol-α distinguished by copurification with DNAprimase (DNApol-α) or 3'-5'exonuclease activity (DNApol-δ), immunoblot analysis with DNApol-α specific antibodies, sensitivity to aphidicolin (both DNApol-α and DNApol-δ sensitive) and BuPdGTP (DNApol-α more sensitive), and processivity measurements with and without PCNA (DNApol-δ has PCNA-inducible high processivity).
Recognition and binding of synthetic template-primers by DNA-polymerase-α holoenzyme studied: at least 4 base pair complementarity is required for efficient binding and incorporation. Results suggest that there are intrinsic aspects to the mechanism of nucleotide incorporation which ensure fidelity of DNA synthesis and may provide insight into mechanism of polymerase translocation along templates.
The nucleotide sequence of DNA polymerase α gene was determined. Expression of the enzyme is closely related to cell proliferation during development.
25bp DNA oligomer containing m4T is used in a gel extension assay to measure the efficiency of incorporation of dATP and dGTP opposite m4T using a DNA polymerase α-primase complex. The DNA polymerase α shows a clear preference for pairing with dGTP.