Keratin intermediate filament chains in the European common wall lizard (Podarcis muralis) and a potential keratin filament crosslinker

• Published in: Journal of structural biology 2021-12, Vol.213 (4), p.107793-107793, Article 107793
• Main Authors: Parry, David A.D., Winter, David J.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Cysteine - chemistry; Cysteine - genetics; Cysteine - metabolism; Cytoskeleton - metabolism; Epidermal appendages; Epidermis - metabolism; Epithelium - metabolism; Filament crosslinker; Glycine - chemistry; Glycine - genetics; Glycine - metabolism; Intermediate Filaments - chemistry; Intermediate Filaments - genetics; Intermediate Filaments - metabolism; Keratin intermediate filament chains; Keratins - chemistry; Keratins - genetics; Keratins - metabolism; Lizard keratin; Lizards - classification; Lizards - genetics; Lizards - metabolism; Multigene Family - genetics; Proline - chemistry; Proline - genetics; Proline - metabolism; Sequence Homology, Amino Acid; Sequence repeats; Species Specificity
• ISSN: 1047-8477; 1095-8657
• DOI: 10.1016/j.jsb.2021.107793

•Sequences of 28 Type I and II KIF chains in common wall lizard.•Type I and II genes lie in clusters on chromosomes 13 and 2 respectively.•Heads and tails of KIF chains contain many sequences repeats.•H1 subdomain (Type II) is conserved and has a role in assembly.•Potential KIF crosslinker with tandem repeats in tail is identified. On the basis of sequence homology with mammalian α-keratins, and on the criteria that the coiled-coil segments and central linker in the rod domain of these molecules must have conserved lengths if they are to assemble into viable intermediate filaments, a total of 28 Type I and Type II keratin intermediate filament chains (KIF) have been identified from the genome of the European common wall lizard (Podarcis muralis). Using the same criteria this number may be compared to 33 found here in the green anole lizard (Anole carolinensis) and 25 in the tuatara (Sphenodon punctatus). The Type I and Type II KIF genes in the wall lizard fall in clusters on chromosomes 13 and 2 respectively. Although some differences occur in the terminal domains in the KIF chains of the two lizards and tuatara, the similarities between key indicator residues – cysteine, glycine and proline – are significant. The terminal domains of the KIF chains in the wall lizard also contain sequence repeats commonly based on glycine and large apolar residues and would permit the fine tuning of physical properties when incorporated within the intermediate filaments. The H1 domain in the Type II chain is conserved across the lizards, tuatara and mammals, and has been related to its role in assembly at the 2–4 molecule level. A KIF-like chain (K80) with an extensive tail domain comprised of multiple tandem repeats has been identified as having a potential filament-crosslinking role.