Mutations in the helix termination motif of mouse type I IRS keratin genes impair the assembly of keratin intermediate filament.
Two classical mouse hair coat mutations, Rex (Re) and Rex wavy coat (Re(wc)), are linked to the type I inner root sheath (IRS) keratin genes of chromosome 11. An N-ethyl-N-nitrosourea-induced mutation, M100573, also maps close to the type I IRS keratin genes. In this study, we demonstrate that Re and M100573 mice bear mutations in the type I IRS gene Krt25; Re(wc) mice bear an additional mutation in the type I IRS gene Krt27. These three mutations are located in the helix termination motif of the 2B alpha-helical rod domain of a type I IRS keratin protein. Immunohistological analysis revealed abnormal foam-like immunoreactivity with an antibody raised to type II IRS keratin K71 in the IRS of Re/+ mice. These results suggest that the helix termination motif is essential for the proper assembly of types I and II IRS keratin protein complexes and the formation of keratin intermediate filaments.
Tanaka
Shigekazu
S
Mammalian Genetics Laboratory, Genetic Strains Research Center, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, Japan.
Miura
Ikuo
I
Yoshiki
Atsushi
A
Kato
Yoriko
Y
Yokoyama
Haruka
H
Shinogi
Akiko
A
Masuya
Hiroshi
H
Wakana
Shigeharu
S
Tamura
Masaru
M
Shiroishi
Toshihiko
T
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D008040:Genetic Linkage; D006197:Hair / Q000378:metabolism / Q000473:pathology; D018859:Hair Follicle / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D007382:Intermediate Filaments / Q000737:chemistry / Q000378:metabolism; D053564:Keratins, Hair-Specific / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics*; D051379:Mice; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010802:Phylogeny; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid
D053564:Keratins, Hair-Specific; D004247:DNA