Structure and function of nonhistone phosphoproteins

Abstract

Many nonhistone nuclear proteins have been shown to be phosphorylated and associated with a diverse range of cellular activities. The aim of this present review is to update the most recent developments in this field with respect to the traditional roles that these proteins have been postulated to play as enzymes, DNA-binding proteins, hormonal receptors, nucleosome associated proteins, and nucleolar associated proteins. In addition, evidence is presented suggesting that these proteins may also function as nuclear oncogene protein products, structural constituents of nuclear organization (e.g., lamina-nuclear matrix associated proteins), and RNA processing factors.

Rapid Phosphorylation of H3 Histone in Isolated Nuclei of Barley (Hordeum vulgare L.)

“…This is true of all nuclear preparations from barley with different light pretreatment. Most of the nuclear protein kinases previously described (Halikowski et Liew, 1988) have higher activity with Mg2+ ions. All further experiments were performed in the presence of 20 mM Mg2+ or 5 mM Mn2+ ions.…”

“…This may be explained by the presence of many different nuclear protein kinases in our preparations. Plants (Ranjeva and Boudet, 1987) and other eukaryotes (Halikowski and Liew, 1988;van Holde, 1989) are known to have many nuclear protein kinases.…”

“…Light absorbed by phytochrome has been shown to affect the expression ofdifferent genes (Tobin and Silverthorne, 1985;Nagy et al, 1988). Phosphorylation of non-histone chromatin proteins (NHCP) has been demonstrated to be involved in several regulatory processes in gene expression, RNA transcription, ribonucleoprotein (RNP) particle assembly and nuclear substructure regulation (Kleinsmith, 1978;Halikowski et Liew, 1988). However, little is known about the signal transduction chain, from excitation of phytochrome to changes in gene expression.…”

Monoclonal Antibodies Against Nuclear Casein Kinase NII (PK-N2)

“…However, similar protein kinases have also been identified in the cell nucleus, and appear to be the counterpart of the cytoplasmic casein kinases; they have been termed N I and N II (designated here as PK-N1 and PK-N2, respectively). These protein kinases have been implicated in the phosphorylation of a variety of nuclear-associated proteins such as non-histone proteins, RNA polymerases, etc., thereby playing a possible role in the control of gene activity (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). In previous work, we have documented that rat ventral prostatic PK-N2 is remarkably sensitive to androgenic status in the animal which may be Abbreviations and trivial names: PK-N2, nuclear casein kinase II; CK-2, cytoplasmic casein kinase II; CK-1, cytoplasmic casein kinase I; PK-N1, nuclear casein kinase I; ELISA, enzyme-linked immunosorbent assay; PMSF, phenylmethylsulfonyl fluoride; TMB, tetramethylbenzidine; DTT, dithiothreitol; PEG, polyethylene glycol; PBS, phosphate buffered saline; TBS, Tris buffered saline; BSA, bovine serum albumin; HAT medium, medium containing hypxanthine, aminopterin, and thymidine;EDTA, ethylenediamine tetraacetic acid.…”