Sequence variants of chicken linker histone H1.a

Abstract

Two allelic isoforms (H1.a1 and H1.a2) of histone H1.a were identified within two conservative flocks (R11 and R55) of Rhode Island Red chickens. These proteins form three phenotypes: a1, a2 and a1a2. Birds with phenotype a1 were most common (frequency 0.825-0.980) while the a1a2 chickens appeared relatively rarely (0.017-0.175). The third phenotype a2, not detected in the tested populations, has only been revealed in progeny of the purpose-mated a1a2 birds. The polymorphism of histone H1.a was observed in all examined chicken tissues, so that the H1 preparations isolated from the lung, spleen, kidney and testis from the same individual exhibited identical phenotypes (a1, a2, or a1a2). This finding, together with inheritance data, supports the genetic nature of the H1.a polymorphism. As indicated by cleavages with alpha-chymotrypsin and protease V8, the H1.a1 and H1.a2 are two highly related proteins which differ within N-terminal part of their C-terminal tails. Only a single nonconservative amino acid substitution between both H1.a allelic isoforms was detected by Edman degradation: glutamic acid present at position 117 in histone H1.a1 was replaced by lysine in histone H1.a2. Furthermore, using microsequencing techniques we have found a sequence homology between the N- and C-terminal parts of an unknown minor protein H1.y, present in the phenotype a2, and similar regions of histone H1.b.

A shift in erythrocyte histone H1 complement following selection in quail (Coturnix japonica)

“…Acting as peculiar modifiers of chromatin organization, the histone H1 subtypes may control expression of individual genes that influence many important cellular processes, such as chromosome alignment and segregation (Takata et al 2007), mitotic progression (Green et al 2010), and DNA damage response (Kratzmeier et al 1999;Hashimoto et al 2007). Since histone H1 condensing function is mediated by a specific C-terminal domain amino acid composition (Hansen et al 2006;Lu et al 2009), the alterations in the C-terminal domain amino acid sequence (Kosterin et al 1994;Palyga et al 2000;Gornicka-Michalska et al 2006;Kowalski et al 2011a, b) seem to support functional diversity of these chromatin proteins. A specific role for the histone H1 allelic isoform might be assigned based on the cause and effect relationship between the appearance and/or disappearance of a given allele leading to the characteristic phenotypic effects (Kowalski and Palyga 2012a).…”

“…Many histone H1 non-allelic subtypes may consist of allelic isoforms, thus the presence of allelic polymorphism is a distinctive feature of this histone class (Kowalski and Palyga 2012a). Since histone H1 allelic variants were shown to differ in the C-terminal domains (Palyga et al 2000;Berdnikov et al 2003;Sarg et al 2005;Gornicka-Michalska et al 2006;Bogdanova et al 2007;Villar-Garea and Imhof 2008;Kowalski et al 2011a), they could be able to interact with chromatin through the allele-specific effects as manifested by their fluctuated frequency in a given population (Palyga 1998a;Palyga et al 2000;Kowalski and Palyga 2014).…”

“…Out of eight histone H1 subtypes (H1.a, H1.a′, H1.b, H1.b′, H1.c, H1.c′, H1.d, and H1.z) identified among avian erythrocyte histone H1 (Palyga 1991), five, including H1.a in duck (Anas platyrhynchos) (Kowalski et al1998), chicken (Gallus gallus) (Gornicka-Michalska et al 2006) and quail (Coturnix japonica) (Palyga 1998a), H1.a′ in grey partridge (Perdix perdix) (Kowalski et al 2008), H1.b in quail (Palyga 1998a), duck (Palyga et al 2000) and guinea fowl (Numidea meleagris) (Kowalski et al 2011a), H1.c in pheasant (Phasianus colchicus) (Kowalski et al 2010) and guinea fowl (Kowalski et al 2011a), and H1.z in duck (Palyga et al 1993) and quail (Palyga 1998a), have been recognized to be polymorphic due to the presence of two or three electromorphs differently migrating in the polyacrylamide gels as a result of variation in their net charges and/or apparent molecular weights. Both frequent and rare allelic isoforms for the avian polymorphic histone H1 subtypes were already observed in both conservative (Kowalski et al 1998;Palyga et al 2000;Kowalski and Palyga 2014) and breeding populations (Palyga et al 1993;Palyga 1998b;Kowalski and Palyga 2014).…”

High-Resolution Two-Dimensional Polyacrylamide Gel Electrophoresis: A Tool for Identification of Polymorphic and Modified Linker Histone Components

“…Two-dimensional PAGE can also be used as a preparatory step for protein identification in gel pieces by mass spectrometry (Fig. 9) (Górnicka-Michalska et al, 2006;Kowalski et al, 2009) or for gathering a greater amount of concentrated protein to protease cleavage (Górnicka-Michalska et al, 2006;Kowalski et al, 2011) (Fig. 10) and microsequencing (Górnicka-Michalska et al, 2006).…”

“…This electrophoretic system is relatively straightforward and reproducible. Beside qualitative and quantitative applications (Kowalski et al, 2011a(Kowalski et al, , 2011b for protein detection and subsequent abundance estimation, the 2D-PAGE-like method may also be used on a preparative scale to enable gathering and purification of appropriate amount of the resolved protein for subsequent structural analyses including chemical cleavage and enzymatic digestion Pałyga & Neelin, 1998;Pałyga et al, 2000;Kowalski et al, 2011aKowalski et al, , 2011b as well as amino acid sequencing (Górnicka-Michalska et al, 2006) and mass spectrometry analysis (Kowalski et al, 2009).…”