|Purification and characterization of the messenger ribonucleoprotein-associated casein kinase II of Artemia salina cryptobiotic gastrulae|Thoen, C.; Van Hove, L.; Piot, E.; Slegers, H. (1984). Purification and characterization of the messenger ribonucleoprotein-associated casein kinase II of Artemia salina cryptobiotic gastrulae. Biochim. Biophys. Acta 783(2): 105-113. dx.doi.org/10.1016/0167-4781(84)90001-0
In: Biochimica et Biophysica Acta. Elsevier: Amsterdam. ISSN 0006-3002, more
Messenger ribonucleoprotein; Protein kinase; Subunit composition; (A. salina)
|Authors|| || Top |
- Thoen, C.
- Van Hove, L.
- Piot, E.
- Slegers, H.
The mRNP-associated protein kinase is purified to near homogeneity by ion-exchange chromatography on phosphocellulose and affinity chromatography on casein-Sepharose 4B and ATP-agarose. The cyclic nucleotide-independent enzyme phosphorylates casein using either ATP or GTP. The enzyme exists in two forms composed of subunits with Mr 36 500 (α) and 28 000 (β) and of subunits with Mr 36 500 (α), 33 000 (α′) and 28 000 (β). The undegraded enzyme has an Mr of 136 000 ± 7000. The enzyme is inhibited by heparin and hemin and stimulated by spermine. The mRNP-associated protein kinase may be classified as a casein kinase II. Main mRNP protein phosphate acceptors have Mr values of 112 000, 72 000, 65 000, 53 000, 38 000, 28 000, 23 500 and 21 000. Phosphorylation of the Mr 38 000 poly(A)-binding protein resulted in the generation of different acidic ionic species. From the observed inhibition of the translational activity after phosphorylation by the mRNP-associated protein kinase a function in the repression of mRNP is proposed.