Polo kinase, l(3)01673, l(3)77Aa, Plk1
protein kinase - regulates mitosis - participates in the control of mitotic progression by targeting Cdc25/String - centrosome-specific phosphorylation of Cnn by Polo/Plk1 drives Cnn scaffold assembly and centrosome maturation - Cdk1 phosphorylates Sas-4 to recruit Polo to daughter centrioles and convert them to centrosomes
Low-frequency RNA-Seq exon junction(s) not annotated.
Gene model reviewed during 5.45
576 (aa); 65 (kD observed)
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\polo using the Feature Mapper tool.
polo transcripts are present throughout development and are particularly abundant in early embryos and adult females. They are observed throuhgout the syncytial embryo and in a cortical layer in the blastoderm embryo by in situ hybridization. Following cellularization, the polo transcript distribution broadly correlates with regions of the embyro undergoing divisions. polo transcripts are also found in larval tissues containing diploid cells such as testis, imaginal discs, and brain. Within these, expression is strongest in cells undergoing proliferation. In the brain, these include the proliferating centers in the optic lobes and the parts of the ventral ganglion giving rise to thoracic innervation.
polo protein is present at low levels in the oocyte until stage S11 or S12 after which it fills the oocyte cytoplasm from stage S12 to S13 on.
polo protein localizes at centrosomes early in mitosis and simultaneously, some staining is associated with metaphase chromosomes. Centrosome staining is progressively lost during anaphse-telophase with a concurrent increase in midbody staining. By the end of telophase, staining is only found in the midbody.
GBrowse - Visual display of RNA-Seq signalsView Dmel\polo in GBrowse 2
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.
Source for merge of polo anon-WO0172774.3 was sequence comparison ( date:051113 ).
RNAi screen using dsRNA made from templates generated with primers directed against this gene causes decreased γ-tubulin staining at the spindle pole and detachment of the pole when assayed in S2 cells. This phenotype can be observed when the screen is performed with or without Cdc27 dsRNA.
S2 cells treated with dsRNA generated against this gene show reduced phagocytosis of Candida albicans compared to untreated cells.
S2 cells transfected with dsRNA made from templates generated with primers directed against this gene show metaphase arrest.
When dsRNA constructs are made and transiently transfected into S2 cells in RNAi experiments, an increase in the proportion of G2/M phase cells, an increase, a decrease in cytokinetic index in mitotic index, a decrease in the ratio of cells in prometaphase and metaphase versus the total number of mitotic cells, a whole range of mitotic abnormalities, spindle abnormalities, centrosome abnormalities (no γ-tubulin at the poles) are seen.
dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.
RNAi screen using dsRNA made from templates generated with primers directed against this gene causes a phenotype when assayed in Kc167 and S2R+ cells: cell morphology is aberrant and there is an increased frequency of microtubule-based mitotic spindles, indicative of a failure in mitosis.
Females homozygous for hypomorphic mutations in polo show defects both in the organisation of the central microtubule organising centre at meiosis II and in sperm aster formation.
A series of biochemical experiments demonstrate that polo is a Ser/Thr protein kinase which has to be phosphorylated to show kinase activity. Putative substrates (a β-tubulin and an 85kD microtubule-associated protein) can be specifically phosphorylated by polo.
Five genes essential for cell cycle progression, polo, mgr, asp, stg and gnu, are recombined onto a single chromosome, EMS mutations are isolated that fail to complement this chromosome. Genes encoding proteins that interact with the products of any of the five genes are isolated.
Mutations in polo lead to a variety of spindle defects including monopolar structures in larval brains and multipolar spindles in male meiosis. Embryos from mothers transheterozygous for mutations in polo and scant show bipolar spindles that have a centrosome only at one pole.
polo gene product immunoprecipitated from single Drosophila embryos can phosphorylate casein in vitro, and the kinase activity peaks cyclically at late anaphase/telophase. This contrasts with the cycling of CycB-associated cdc2 histone H1 kinase, which is maximal upon entry into mitosis during the rapid syncitial mitoses. The polo product may regulate microtubule behaviour.
Immunocytological approach is used to address the behaviour of essential mitotic gene products in embryonic cell cycles.