4yyp
From Proteopedia
Crystal structure of human PLK4-PB3 in complex with STIL-CC
Structural highlights
Disease[STIL_HUMAN] Precursor T-cell acute lymphoblastic leukemia;Autosomal recessive primary microcephaly. A chromosomal aberration involving STIL may be a cause of some T-cell acute lymphoblastic leukemias (T-ALL). A deletion at 1p32 between STIL and TAL1 genes leads to STIL/TAL1 fusion mRNA with STIL exon 1 slicing to TAL1 exon 3. As both STIL exon 1 and TAL1 exon 3 are 5'-untranslated exons, STIL/TAL1 fusion mRNA predicts a full length TAL1 protein under the control of the STIL promoter, leading to inappropriate TAL1 expression. In childhood T-cell malignancies (T-ALL), a type of defect such as STIL/TAL1 fusion is associated with a good prognosis. In cultured lymphocytes from healthy adults, STIL/TAL1 fusion mRNA may be detected after 7 days of culture. The disease is caused by mutations affecting the gene represented in this entry. Function[PLK4_HUMAN] Serine/threonine-protein kinase that plays a central role in centriole duplication. Able to trigger procentriole formation on the surface of the parental centriole cylinder, leading to the recruitment of centriole biogenesis proteins such as SASS6, CENPJ/CPAP, CCP110, CEP135 and gamma-tubulin. When overexpressed, it is able to induce centrosome amplification through the simultaneous generation of multiple procentrioles adjoining each parental centriole during S phase. Phosphorylates 'Ser-151' of FBXW5 during the G1/S transition, leading to inhibit FBXW5 ability to ubiquitinate SASS6. Its central role in centriole replication suggests a possible role in tumorigenesis, centrosome aberrations being frequently observed in tumors. Also involved in trophoblast differentiation by phosphorylating HAND1, leading to disrupt the interaction between HAND1 and MDFIC and activate HAND1. Phosphorylates CDC25C and CHEK2.[1] [2] [3] [4] [5] [6] [STIL_HUMAN] Immediate-early gene. Plays an important role in embryonic development as well as in cellular growth and proliferation; its long-term silencing affects cell survival and cell cycle distribution as well as decreases CDK1 activity correlated with reduced phosphorylation of CDK1. Plays a role as a positive regulator of the sonic hedgehog pathway, acting downstream of PTCH1.[7] [8] Publication Abstract from PubMedPolo-like kinases (PLK) are eukaryotic regulators of cell cycle progression, mitosis and cytokinesis; PLK4 is a master regulator of centriole duplication. Here, we demonstrate that the SCL/TAL1 interrupting locus (STIL) protein interacts via its coiled-coil region (STIL-CC) with PLK4 in vivo. STIL-CC is the first identified interaction partner of Polo-box 3 (PB3) of PLK4 and also uses a secondary interaction site in the PLK4 L1 region. Structure determination of free PLK4-PB3 and its STIL-CC complex via NMR and crystallography reveals a novel mode of Polo-box-peptide interaction mimicking coiled-coil formation. In vivo analysis of structure-guided STIL mutants reveals distinct binding modes to PLK4-PB3 and L1, as well as interplay of STIL oligomerization with PLK4 binding. We suggest that the STIL-CC/PLK4 interaction mediates PLK4 activation as well as stabilization of centriolar PLK4 and plays a key role in centriole duplication. STIL binding to Polo-box 3 of PLK4 regulates centriole duplication.,Arquint C, Gabryjonczyk AM, Imseng S, Bohm R, Sauer E, Hiller S, Nigg EA, Maier T Elife. 2015 Jul 18;4. doi: 10.7554/eLife.07888. PMID:26188084[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Human | Large Structures | Polo kinase | Arquint, C | Boehm, R | Gabryjonczyk, A | Hiller, S | Imseng, S | Maier, T | Nigg, E A | Sauer, E | Complex | Polo-box | Transferase
