Molecular cloning and expression of mRNAs encoding H1 histone and an H1 histone-like sequences in root tips of pea (Pisum sativum L.)

Abstract

Two cDNA clones representing mRNAs, highly expressed in pea root tips, were isolated by mRNA differential display. Ribonuclease protection analyses showed different patterns of expression of these two messages in several pea tissues. Sequence analysis showed that the first clone, PsH1b-40, has 100% homology with a previously isolated H1 histone cDNA, PsH1b. However, it has an additional 30 nt at the 3' end which is absent in PsH1b, suggesting possible multiple polyadenylation sites in the same mRNA. The second clone, PsH1b-41, encodes a deduced 19.5 kDa protein of 185 amino acids with an isoelectric point of 11.5. The putative globular domain of the encoded protein showed 67-71% residue identity with globular domains of 28 kDa pea PsH1b H1 histone and Arabidopsis thaliana H1-1 H1 histone. It has 9 repeating motifs of (T/S)XXK. In the C-terminal domain, there are four lysine-rich repeating motifs of SXK(T/S)PXKKXK which may be involved in chromatin condensation and decondensation. Southern blot analysis of nuclear DNA shows that PsH1-41 belongs to a multigene family.

Differential Expression of Proteins and mRNAs from Border Cells and Root Tips of Pea

“…Comparable results were obtained for a differentially expressed band, HI histone (Woo et al, 1995). Using the differential display cDNA clone as a probe, two HI histones were identified, one with 100% homology to a previously identified pea HI histone, PsHlb (Gantt and Key, 1987), and one to a new pea HI histone sequence that has 59.1% homology to PsHlb (Woo et al, 1995). Both were shown by RNase protection to be differentially expressed in several pea tissues in a manner comparable to their deduced expression in the mRNA differential display gels.…”

“…Results of northern analysis and RNase protection showed the message to be equally expressed in all tissue, consistent with the results from mRNA differential display gels. Comparable results were obtained for a differentially expressed band, HI histone (Woo et al, 1995). Using the differential display cDNA clone as a probe, two HI histones were identified, one with 100% homology to a previously identified pea HI histone, PsHlb (Gantt and Key, 1987), and one to a new pea HI histone sequence that has 59.1% homology to PsHlb (Woo et al, 1995).…”

Structure of allelic variants of subtype 5 of histone H1 in pea Pisum sativum L.

“…The previously characterised His1 gene maps to another chromosome, while His5 is tightly linked to the genes coding for other subtypes. We are now in a position to consider the remaining two DNA sequences available that are presumed to encode H1 histones, H1.b (Gantt and Key, 1987) and H1.41 (Woo et al, 1995).…”

“…This result was confirmed for H1-1 from the sequence of its gene (Berdnikov et al, 2003). The derived amino-acid sequences of other H1 genes, H1.b (Gantt and Key, 1987) and H1.41 (Woo et al, 1995), display phenylalanine at the corresponding position. Considering that phenylalanine is generally conserved in plant histones H1, the lack of N-bromosuccinimide cleavage in H1-2, H1-3, H1-4 and H1-6 is probably a result of the presence of the tripeptide FKL at the border of G-domain.…”

“…Only His1 has been coupled with its DNA sequence (Berdnikov et al, 2003). Gantt and Key (1987) sequenced cDNA coding for a H1 subtype, and Woo et al (1995) described the sequence of a putative histone H1; however, the relation of these two sequences to His1-His7 is unclear.…”