A novel histone variant localized in nucleoli of higher plant cells

Abstract

Immunofluorescence staining with antisera raised against p35, a basic nuclear protein that accumulates in the pollen nuclei of Lilium longiflorum, specifically stained the nucleoli in interphase nuclei of somatic tissues, including root and leaf, and in pachytene nuclei during meiotic division, whereas antisera raised against histone H1 uniformly stained the entire chromatin domain with the exception of the nucleoli in these nuclei. Further, p35-specific antisera stained the nucleoli in root and leaf nuclei of the monocotyledonous plants Tulipa gesneriana, Allium cepa and Triticum aestivum and of the dicotyledonous plants Vicia faba and Nicotiana tabacum. Thus, these novel antisera stained the nucleoli in cells of all higher plants examined, although the staining patterns within nucleoli were somewhat different among plant species and tissues. The full-length cDNA of p35 was cloned on the basis of the partial amino acid sequence. The deduced amino acid composition and amino acid sequence of p35 indicate that this nucleolar protein is a novel variant of histone Hl. Further, p35 was strongly bound to ribosomal DNA in vitro. The results of immunoblotting of histones extracted from each tissue of the various plant species with the nucleolus-specific antibodies also suggested the conservation of similar epitope(s) in both mono- and dicotyledonous plants. From these results, it is suggested that similar variants of histone Hl are specifically distributed in the nucleoli of all plant species and help to organize the nucleolar chromatin.

Histone H1 of Trypanosoma cruzi Is Concentrated in the Nucleolus Region and Disperses upon Phosphorylation during Progression to Mitosis

“…Histone H1x, a subtype located in chromatin regions not affected by micrococcus nuclease (25), is also located in the nucleolus region at G 1 phase (44). In plants a histone H1 variant called p35 is also enriched in the nucleolus (46). In yeast, it represses recombination at the ribosomal DNA locus (32).…”

Expression profiles of a banana fruit linker histone H1 gene MaHIS1 and its interaction with a WRKY transcription factor

“…Some reports have shown that linker histone H1 were preferentially localized in the cell nucleus (Ascenzi and Gantt 1999;Tanaka et al 1999;Folco et al 2003). To determine the subcellular localization of MaHIS1 protein, the coding region of MaHIS1 was fused in-frame with the GFP gene, and the resulting constructs were then transfected into tobacco BY-2 protoplasts.…”

Distribution of linker histone variants during plant cell differentiation in the developmental zones of the maize root, dedifferentiation in callus culture after auxin treatment

“…Several H1 variants have been studied in both animal and plant organisms and most of them are considered tissue-or stage-specific, while others are accumulated during cell differentiation or in response to specific environmental signals (Jerzmanowski et al, 2000, Khochbin, 2001). For instance, in several liliaceous plants specific histone H1 variants appear during male meiosis (Ueda and Tanaka, 1995), other variants expressed during water deficit have been identified in several monocots and dicots (Scippa et al, 2004) whereas a specific H1 variant has been found to localize in nucleoli of higher plant cells (Tanaka et al, 1999).…”

“…Although linker histones have been studied in several plant species (Ivanchenko et al, 1987, Srebreva et al, 1989, Tanaka et al, 1999, Jerzmanowski et al, 2000, Scippa et al, 2004, little is known about their spacial distribution during plant cell differentiation and dedifferentiation, processes that involve several alterations in chromatin structure and function. Even less is known about the effect of exogenous applied hormones on linker histone distribution, although there is evidence about alterations in histone H1 patterns after hormone treatment of animal cells (Wurtz, 1985).…”