Molecular structure of the human desmoplakin I and II amino terminus.
Desmoplakins (DPs) I and II are closely related proteins found in the innermost region of the desmosomal plaque, which serves as a cell surface attachment site for cytoplasmic intermediate filaments. Overlapping cDNA clones comprising 9.2 kilobases of DP-I, predicted to encode a full-length 310-kDa polypeptide (2677 amino acid residues), have now been identified. Here we report the predicted protein sequence and structural analysis of the N terminus of DP, extending our previous study of the rod and carboxyl domains. The N terminus contains groups of heptad repeats that are predicted to form at least two major alpha-helical-rich bundles. Unlike the rod and carboxyl domains, the N terminus did not display a periodic distribution of charged residues. Northern blot mapping and genomic sequence analysis were also undertaken to examine the organization of the DP mRNAs. A 1-kilobase intron was located at the 3' boundary of a DP-I-specific region; however, instead of an intron at the 5' junction, a possible splice donor site was observed within a potential coding sequence, suggesting alternative RNA splicing from an internal donor site.
Virata
M L
ML
Department of Pathology, Northwestern University Medical School, Chicago, IL 60611.
Wagner
R M
RM
Parry
D A
DA
Green
K J
KJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000235:genetics; D051180:Desmoplakins; D003896:Desmosomes / Q000648:ultrastructure; D006801:Humans; D015603:Keratinocytes / Q000502:physiology; D008969:Molecular Sequence Data; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D016415:Sequence Alignment
D003598:Cytoskeletal Proteins; C495294:DSP protein, human; D051180:Desmoplakins; D012333:RNA, Messenger