Purification of rat liver nuclear protein kinase NI

Thornburg, William; O'Malley, Anthony F.; Lindell, Thomas J.

doi:10.1016/s0021-9258(17)30436-2

Cited by 68 publications

(2 citation statements)

References 26 publications

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“…The cytosolic and membraneassociated forms of CKI appear to be monomers of 30-37 kDa (Ashmad et al, 1984;Kitagawa & Racker, 1982). Nuclear forms of the enzyme have apparent molecular masses ranging from 25 to 55 kDa (Thornburg et al, 1978;Rikans & Ruddon, 1976). CKI exists in all species and cell types examined (Tuazon & Traugh, 1991).…”

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confidence: 99%

Casein Kinase I α and αL: Alternative Splicing-Generated Kinases Exhibit Different Catalytic Properties^,

et al. 1996

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Casein kinase I (CKI) is a family of serine/threonine protein kinases found in all eukaryotes examined to date. Here, the rat CKI isoforms alpha and alpha L were cloned and expressed in both eukaryotic and prokaryotic systems. Characterization of the genomic DNA flanking the exon unique to CKI alpha L demonstrated that CKI alpha and CKI alpha L arise by the alternative splicing of a common pre-mRNA molecule. To the best of our knowledge, the alpha L isoform is the only known active serine/threonine kinase to contain an insert within its catalytic domain. Tissue distribution of each splicing isoform was examined by RT-PCR, immunoprecipitation, and Western blotting. Both isoforms were expressed in all tissues tested but at different levels. Bacterially expressed CKI alpha isoforms were active and therefore biochemically characterized. CKI alpha and CKI alpha L proteins were demonstrated to have casein kinase I catalytic properties. More importantly, the recombinant isoform proteins exhibited differences in binding and activity toward common CKI substrates. These observations demonstrate that the alpha L insert within the kinase domain modulates substrate kinetics. These kinetic differences suggest that CKI alpha and CKI alpha L may perform different biological roles.

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confidence: 99%

Casein Kinase I α and αL: Alternative Splicing-Generated Kinases Exhibit Different Catalytic Properties^,

et al. 1996

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“…The most thoroughly characterized nuclear protein kinases are not stimulated by cyclic nucleotides nor inhibited by the regulatory subunit or heat-stable inhibitor of the cyclic-AMPdependent protein kinase. Thornburg & Lindell (1977) and Thornburg et al (1978) purified two enzymes, NI and NIL NI displays the substrate preferences: casein > phosvitin > histone H2B.…”

Section: P Rotein Kinases From the Nucleusmentioning

confidence: 99%

Phosphorylation of nuclear proteins

Laskey

1983

Phil. Trans. R. Soc. Lond. B

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Many nuclear proteins are phosphorylated: they range from enzymes to several structural proteins such as histones, non-histone chromosomal proteins and the nuclear lamins. The pattern of phosphorylation varies through the cell cycle. Although histone H1 is phosphorylated during interphase its phosphorylation increases sharply during mitosis. Histone H3, chromosomal protein HMG 14 and lamins A, B and C all show reversible phosphorylation during mitosis. Several nuclear kinases have been characterized, including one that increases during mitosis and phosphorylates H1 in vitro. Factors have been demonstrated in maturing amphibian oocytes and mitotic mammalian cells that induce chromosome condensation and breakdown of the nuclear membrane. The possibility that they are autocatalytic protein kinases is considered. The location of histone phosphorylation sites within the nucleosome is consistent with a role for phosphorylation in modulating chromatin folding.

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Topoisomerase I phosphorylation in vitro and in rapidly growing Novikoff hepatoma cells.

Durban¹,

Goodenough²,

Mills³

et al. 1985

The EMBO Journal

107

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Changes in phosphorylation modulate the activity of topoisomerase I in vitro. Specifically, enzymatic activity is stimulated by phosphorylation with a purified protein kinase (casein kinase type II). The purpose of this study was to compare the sites that are phosphorylated in vitro by casein kinase type II with the site(s) phosphorylated in vivo in rapidly growing Novikoff hepatoma cells. Topoisomerase I labeled in vitro was characterized by three major tryptic phosphopeptides (I‐III). Separation of these peptides by a C18‐reverse phase h.p.l.c. column resulted in their elution at fractions 18 (I), 27 (II) and 44 (III) with 17%, 22.5% and 33% acetonitrile, respectively. In contrast, only one major phosphopeptide was identified by h.p.l.c. in topoisomerase I labeled in vivo. This phosphopeptide eluted at fraction 18 corresponding to the elution properties of phosphopeptide I labeled in vitro. It also co‐migrated with tryptic phosphopeptide I when subjected to high‐voltage electrophoresis on thin‐layer cellulose plates. Preliminary experiments suggest that phosphorylation occurs at a serine residue six amino acids from the N‐terminus of the peptide. These data indicate that topoisomerase I is phosphorylated in vivo and in vitro within the same tryptic peptide and suggest that topoisomerase I is phosphorylated in vivo by casein kinase II.

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Purification of rat liver nuclear protein kinase NI

Cited by 68 publications

References 26 publications

Casein Kinase I α and αL: Alternative Splicing-Generated Kinases Exhibit Different Catalytic Properties^,

Casein Kinase I α and αL: Alternative Splicing-Generated Kinases Exhibit Different Catalytic Properties^,

Phosphorylation of nuclear proteins

Topoisomerase I phosphorylation in vitro and in rapidly growing Novikoff hepatoma cells.

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Purification of rat liver nuclear protein kinase NI

Cited by 68 publications

References 26 publications

Casein Kinase I α and αL: Alternative Splicing-Generated Kinases Exhibit Different Catalytic Properties,

Casein Kinase I α and αL: Alternative Splicing-Generated Kinases Exhibit Different Catalytic Properties,

Phosphorylation of nuclear proteins

Topoisomerase I phosphorylation in vitro and in rapidly growing Novikoff hepatoma cells.

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Product

Resources

About

Casein Kinase I α and αL: Alternative Splicing-Generated Kinases Exhibit Different Catalytic Properties^,

Casein Kinase I α and αL: Alternative Splicing-Generated Kinases Exhibit Different Catalytic Properties^,