Purification of Golgi casein kinase from bovine milk

DUNCAN, Jennifer S.; WILKINSON, Mark C.; Burgoyne, Robert D.

doi:10.1042/0264-6021:3500463

Cited by 16 publications

(14 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2B). A minor peak of activity eluting with about 0.55 M NaCl was also generally observed, possibly reflecting heterogeneity of the kinase, as also suggested by others [12]. The more retarded peak, however, underwent rapid inactivation and was not further investigated.…”

Section: G-ck Accounts For the Whole Casein Kinase Activity Of The Gomentioning

confidence: 57%

“…While the biochemical characterization of G-CK with special reference to the definition of its substrate specificity was quite straightforward thanks to the availability of fairly active G-CK preparations from the Golgi apparatus of lactating mammary gland and the synthesis of appropriate phosphoacceptor peptide substrates, the elucidation of the primary structure of G-CK turned out to be a troublesome and frustrating task. In fact, despite the recurrent efforts of several laboratories [11,12,[19][20][21][22][23][24][25][26], G-CK could not be purified to homogeneity, a situation which has hindered up to now any reliable structural analysis of this elusive kinase. This prompted us to address the problem from a different angle, i.e.…”

mentioning

confidence: 99%

“…This latter is differentiated by the position of the crucial acidic determinant which is at position n + 3 instead of being at n + 2 where it is strictly required for recognition by G-CK. Based on this information, a b-casein-derived peptide substrate specifically recognized by G-CK but not by CK2 or any other 'casein kinase' was developed [9] and has been successfully employed for monitoring G-CK in sources other than lactating mammary gland [11,12]. An important outcome of these studies was the detection of G-CK in tissues where casein is not expressed, notably liver, brain, kidney, spleen and salivary gland [11,13], leading to the concept that, similar to CK1 and CK2, G-CK is also not an enzyme dedicated only to the phosphorylation of casein, but is a pleiotropic kinase targeting a wide spectrum of endogenous substrates.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Analysis of a sub-proteome which co-purifies with and is phosphorylated by the Golgi casein kinase

Tibaldi

Arrigoni

Brunati

et al. 2006

Cell. Mol. Life Sci.

View full text Add to dashboard Cite

In an attempt to gain information about the identity of the Golgi apparatus casein kinase(s) (G-CK), responsible for the phosphorylation of caseins in lactating mammary gland, the proteins present in fractions enriched in G-CK activity eluted from DEAE-Sepharose and heparin-Sepharose columns were resolved by two-dimensional electrophoresis and analyzed by mass spectrometry. This led to the identification of 47 proteins altogether, none of which is a bona fide protein kinase. At least 9 of the identified proteins however, are readily phosphorylated by co-purifying G-CK activity, and 7 are physically associated with it to give supramolecular complex(es) of about 500 kDa as judged from Superdex S200 gel fitration and glycerol gradient ultracentrifugation experiments. In contrast, the apparent molecular weight of G-CK estimated from an in gel activity assay after SDSPAGE and renaturation is about 41 kDa. Many of the proteins phosphorylated by and/or associated with G-CK belong to the category of chaperonines, including HSP90, GRP-94 and -78, and various isoforms of protein disulfide isomerases, suggesting a global role of this kinase in the modulation of protein folding.

show abstract

Section: G-ck Accounts For the Whole Casein Kinase Activity Of The Gomentioning

confidence: 57%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Analysis of a sub-proteome which co-purifies with and is phosphorylated by the Golgi casein kinase

Tibaldi

Arrigoni

Brunati

et al. 2006

Cell. Mol. Life Sci.

View full text Add to dashboard Cite

show abstract

“…However, the functional significance of the kinase activity of Vlk in the Golgi remains for future study. Various proteins, including caseins (Duncan et al, 2000;Turner et al, 1993;West and Clegg, 1984), proteoglycan (Glossl et al, 1986) and osteopontin (Lasa et al, 1997), are known to be phosphorylated in the Golgi. Hence, it is possible that Vlk is involved in the phosphorylation of such proteins in the Golgi.…”

Section: Discussionmentioning

confidence: 99%

The novel protein kinase Vlk is essential for stromal function of mesenchymal cells

Kinoshita¹,

Era

Jakt

et al. 2009

Development

View full text Add to dashboard Cite

From a list of protein kinases (PKs) that are newly induced upon differentiation of mouse embryonic stem cells to mesendoderm, we identified a previously uncharacterized kinase, Vlk (vertebrate lonesome kinase), that is well conserved in vertebrates but has no homologs outside of the vertebrate lineage. Its kinase domain cannot be classified into any of the previously defined kinase groups or families. Although Vlk is first expressed in E-cadherin-positive anterior visceral endoderm and mesendoderm, its expression is later confined to E-cadherin-negative mesenchyme. Vlk is enriched in the Golgi apparatus and blocks VSVG transport from the Golgi to the plasma membrane. Targeted disruption of Vlk leads to a defect in lung development and to delayed ossification of endochondral bone. Vlk -/-mice display neonatal lethality due to respiratory failure, with a suckling defect arising from a cleftpalate. Our results demonstrate that Vlk is a novel vertebrate-specific PK that is involved in the regulation of the rate of protein export from the Golgi, thereby playing an important role in the formation of functional stroma by mesenchymal cells.

show abstract

“…Other than the PKC substrates, the 97-kDa protein appeared to be the substrate for phosphorylase b kinase [13]. The 30-kDa casein was the substrate for casein kinase [5]. During nuclear preparation, casein is suggested to comigrate with nuclei [20].…”

Section: Resultsmentioning

confidence: 99%

Modulation by Sphingosine of Phosphorylation of Substrate Proteins by Protein Kinase C in Nuclei from Cow Mammary Gland

Katoh

2004

The Journal of Veterinary Medical Science

View full text Add to dashboard Cite

ABSTRACT. Protein kinase C (PKC) is an enzyme activated by diacylglycerols such as 1-oleoyl-2-acetyl-sn-glycerol (OAG), phospholipids (in particular phosphatidylserine; PS) and Ca 2+ , which regulate a wide variety of intracellular functions by phosphorylating multiple substrate proteins and enzymes. The effect of sphingosine, the backbone moiety of sphingolipids, on PKC activity and phosphorylation of endogenous proteins catalyzed by PKC was investigated in nuclei of cow mammary gland. Sphingosine inhibited nuclear PKC activity when lysine-rich histone was used as the substrate. The sphingosine inhibition of the PKC activity was reversed by the excess addition of PS, but not by OAG or Ca 2+ . Several nuclear proteins, including 56-kDa, 43-kDa, 38-kDa and 36-kDa proteins, were shown to be substrates for PKC. Of the substrate proteins, the 38-kDa and 36-kDa proteins were identified as annexin I, the Ca 2+ /phospholipid-binding protein; the 56-kDa and 43-kDa proteins have not yet been identified. Sphingosine inhibited phosphorylation of the 56-kDa p rotein and the 36-kDa annexin I, whereas it enhanced that of the 43-kDa protein. The 38-kDa annexin I species was unaffected by sphing osine. As with the PKC activity, inhibition by sphingosine of phosphorylation of the 56-kDa protein and 36-kDa annexin I was reversed b y the excess addition of PS, but not by OAG or Ca 2+. In addition, by the excess addition of PS and not by OAG or Ca 2+ , the sphingosineenhanced phosphorylation of the 43-kDa protein was reversed and returned to near the level in the absence of sphingosine. It is suggested that sphingosine is involved in the regulation of PKC-dependent phosphorylation in the nucleus by modulating the association of PKC or its substrates, particularly annexin I, with membrane phospholipids in cow mammary gland. KEY WORDS: annexin I, cow mammary gland, phosphorylation, protein kinase C, sphingosine.J. Vet. Med. Sci. 66(10): 1237-1242, 2004 Protein kinase C (PKC) is a phosphotransferase activated by diacylglycerols, phosphatidylserine (PS) and Ca 2+, and plays an essential role in transmembrane signal transduction [28,36]. Responding to extracellular signals such as hormones, diacylglycerols are transiently produced from phosphatidylinositol-4,5-bisphosphate in the plasma membrane. The diacylglycerols produced increase the affinity of PKC for Ca 2+ as well as for PS, thereby activating PKC. The activated PKC phosphorylates substrate proteins particularly in the plasma membrane, and the phosphorylated proteins regulate diverse biological functions.Other than in the plasma membrane, it has recently been found that PKC is resident in the cell nucleus as well as in other intracellular organelles, or the enzyme is translocated from the cytosol to the nucleus [4,7,20,31,32,42]. In addition, accumulating evidence suggests that a wide variety of lipids, including diacylglycerols, phospholipids, cholesterols, gangliosides and sphingolipids, are distributed in the nucleus and act as second messengers for PKC-dependent phosphorylati...

show abstract

Purification of Golgi casein kinase from bovine milk

Cited by 16 publications

References 15 publications

Analysis of a sub-proteome which co-purifies with and is phosphorylated by the Golgi casein kinase

Analysis of a sub-proteome which co-purifies with and is phosphorylated by the Golgi casein kinase

The novel protein kinase Vlk is essential for stromal function of mesenchymal cells

Modulation by Sphingosine of Phosphorylation of Substrate Proteins by Protein Kinase C in Nuclei from Cow Mammary Gland

Contact Info

Product

Resources

About