Endogenous protein phosphorylation and casein kinase activity during seed development in Araucaria angustifolia

SummaryThe effect of thrombin on the phosphorylating activity of platelet membranes was compared to that of trypsin. Preincubation of non-32P phosphorylated platelet membranes with or without either of these two enzymes resulted in a considerable loss of membrane protein kinase activity which was most severe when trypsin was used. Protein kinase activity and endogenous protein acceptors decreased in parallel. 32P-phosphorylated membranes showed a slow but progressive loss of label which was accelerated by trypsin. Thrombin under these conditions prevented the loss of 32P-phosphate. These results are interpreted to indicate a thrombin-induced destruction of a phosphoprotein phosphatase. The protein kinase activity of phosphorylated platelet membranes using endogenous or exogenous protein substrates showed a significant reduction compared to non-phosphorylated membranes suggesting a deactivation of protein kinase by phosphorylation of platelet membranes. Neither thrombin nor trypsin caused a qualitative change in the membrane polypeptides accepting 32P-phosphate but resulted in quantitative alterations of their ability to become phosphorylated.

Download Full-text

Faculty Opinions recommendation of Drosophila doubletime mutations which either shorten or lengthen the period of circadian rhythms decrease the protein kinase activity of casein kinase I.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1016883.201562 ◽

2004 ◽

Author(s):

Louis Ptacek

Keyword(s):

Protein Kinase ◽

Circadian Rhythms ◽

Kinase Activity ◽

Casein Kinase ◽

Protein Kinase Activity ◽

Casein Kinase I

Download Full-text

Mono-(2-ethylhexyl) Phthalate Rapidly Increases Celsr2 Protein Phosphorylation in HeLa Cells via Protein Kinase C and Casein Kinase 1

Toxicological Sciences ◽

10.1093/toxsci/kfj135 ◽

2006 ◽

Vol 91 (1) ◽

pp. 255-264 ◽

Cited By ~ 8

Author(s):

Stephanie A. Lahousse ◽

Stephanie A. Beall ◽

Kamin J. Johnson

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Protein Phosphorylation ◽

Hela Cells ◽

Casein Kinase ◽

Casein Kinase 1 ◽

Kinase C ◽

Ethylhexyl Phthalate

Download Full-text

Phosphorylation of IkappaBalpha in the C-terminal PEST domain by casein kinase II affects intrinsic protein stability.

Molecular and Cellular Biology ◽

10.1128/mcb.16.4.1401 ◽

1996 ◽

Vol 16 (4) ◽

pp. 1401-1409 ◽

Cited By ~ 143

Author(s):

R Lin ◽

P Beauparlant ◽

C Makris ◽

S Meloche ◽

J Hiscott

Keyword(s):

Triple Point ◽

Cell Activation ◽

Kinase Activity ◽

Casein Kinase Ii ◽

Casein Kinase ◽

Kinase Assay ◽

Intrinsic Stability ◽

Nf Kappab ◽

Constitutive Phosphorylation

The NF-kappaB/Rel transcription factors participate in the activation of immune system regulatory genes and viral early genes including the human immunodeficiency virus type 1 long terminal repeat. NF-kappaB/Rel proteins are coupled to inhibitory molecules, collectively termed IkappaB, which are responsible for cytoplasmic retention of NF-kappaB. Cell activation leads to the phosphorylation and degradation of IkappaBalpha, permitting NG-kappaB/Rel translocation to the nucleus and target gene activation. To further characterize the signaling events that contribute to IkappaBalpha phosphorylation, a kinase activity was isolated from Jurkat T cells that specifically interacted with IkappaBalpha in an affinity chromatography step and phosphorylated IkappaBalpha with high specificity in vitro. By using an in-gel kinase assay with recombinant IkappaBalpha as substrate, two forms of the kinase (43 and 38 kDa) were identified. Biochemical criteria and immunological cross-reactivity identified the kinase activity as the alpha catalytic subunit of casein kinase II (CKII). Deletion mutants of IkappaBalpha delta1 to delta4) localized phosphorylation to the C-terminal PEST domain of IkappaBalpha. Point mutation of residues T-291, S-283, and T-299 dramatically reduced phosphorylation of IkappaBalpha by the kinase in vitro. NIH-3T3 cells that stably expressed wild-type IkappaBalpha (wtIkappaB), double-point-mutated IkappaBalpha (T291A, S283A), or triple-point-mutated IkappaBalpha (T291A, S283A, T299A) under the control of the tetracycline-responsive promoter were generated. Constitutive phosphorylation of the triple point mutant was eliminated in vivo, although tumor necrosis factor-inducible IkappaBalpha degradation was unaffected. In cell lines and in transiently transfected cells, mutation of the CKII sites in IkappaBalpha resulted in a protein with increased intrinsic stability. Together with results demonstrating a role for N-terminal sites in inducer-mediated phosphorylation and degradation of IkappaBalpha, these studies indicate that CKII sites in the C-terminal PEST domain are important for constitutive phosphorylation and intrinsic stability of IkappaBalpha.

Download Full-text

Characterization of the endogenous protein kinase activity of the hepatitis B virus

Research in Chronic Viral Hepatitis ◽

10.1007/978-3-7091-9312-9_6 ◽

1993 ◽

pp. 53-62 ◽

Cited By ~ 2

Author(s):

M. Kann ◽

R. Thomssen ◽

H. G. Köchel ◽

W. H. Gerlich

Keyword(s):

Hepatitis B Virus ◽

Protein Kinase ◽

Hepatitis B ◽

Kinase Activity ◽

Protein Kinase Activity ◽

Endogenous Protein ◽

B Virus

Download Full-text

Arabidopsis MLK3, a Plant-specific Casein Kinase 1, Negatively Regulated Flowering and Phosphorylated Histone H3 in vivo

10.21203/rs.2.16145/v1 ◽

2019 ◽

Author(s):

Zhen Wang ◽

Junmei Kang ◽

Shangang Jia ◽

Tiejun Zhang ◽

Zhihai Wu ◽

...

Keyword(s):

Kinase Activity ◽

Histone H3 ◽

Casein Kinase ◽

Kinase Assay ◽

Wild Type ◽

Serine Threonine Kinase ◽

Altered Expression ◽

Casein Kinase 1 ◽

Threonine Kinase

Abstract Background: Casein kinase 1 (CK1) family members are highly conserved serine/threonine kinase present in most eukaryotes with multiple biological functions. Arabidopsis MUT9-like kinases ( MLKs ) belong to a clade CK1 specific to the plant kingdom and have been implicated collectively in modulating flowering related processes. Three of the four MLKs ( MLK1/2/4 ) have been characterized, however, little is known about MLK3 , the most divergent MLKs. Results: We demonstrated that compared with wild type, mlk3 , a truncated MLK3 , flowered slightly early under long day conditions and ectopic expression of MLK3 rescued the morphological defects of mlk3 , indicating that MLK3 negatively regulates flowering. GA 3 application accelerated flowering of both wild type and mlk3 , suggesting that mlk3 had normal GA response. The recombinant MLK3-GFP was localized in the nucleus exclusively. In vitro kinase assay revealed that the nuclear protein MLK3 phosphorylated histone 3 at threonine 3 (H3T3ph). Mutation of a conserved catalytic residue (Lysine 175) abolished the kinase activity and resulted in failure to complement the early flowering phenotype of mlk3 . Interestingly, the global level of H3T3 phosphorylation in mlk3 did not differ significantly from wild type, suggesting the redundant roles of MLKs in flowering regulation. The transcriptomic analysis demonstrated that 425 genes significantly altered expression level in mlk3 relative to wild type. The mlk3 mlk4 double mutant generated by crossing mlk3 with mlk4 , a loss-of-function mutant of MLK4 showing late flowering, flowered between the two parental lines, suggesting that MLK3 played an antagonistic role to MLK4 in plant transition to flowering. Conclusions: A serine/threonine kinase encoding gene MLK3 is a casein kinase 1 specific to the plant species and represses flowering slightly. MLK3 located in nucleus catalyzes the phosphorylation of histone H3 at threonine 3 in vitro and an intact lysine residue (K175) is indispensible for the kinase activity. This study sheds new light on the delicate control of flowering by the plant-specific CK1 in Arabidopsis.

Download Full-text