title: Arpp/Ankrd2, a member of the muscle ankyrin repeat proteins (MARPs), translocates from the I-band to the nucleus after muscle injury.
abstract: Ankyrin-repeat protein with a PEST motif and a proline-rich region (Arpp), also designated as Ankrd2, is a member of the muscle ankyrin repeat proteins (MARPs), which have been proposed to be involved in muscle stress response pathways. Arpp/Ankrd2 is localized mainly in the I-band of striated muscle. However, it has recently been reported that Arpp/Ankrd2 can interact with nuclear proteins, such as premyelocytic leukemia protein (PML), p53 and YB-1 in vitro. In this study, to determine whether nuclear accumulation of Arpp/Ankrd2 actually occurs, we performed an immunohistochemical investigation of gastrocnemius muscles that had been injured by injection of cardiotoxin or contact with dry ice. We found that Arpp/Ankrd2 accumulated in the nuclei of myofibers located adjacent to severely damaged myofibers after muscle injury. Double-labeled immunohistochemistry revealed that Arpp/Ankrd2 accumulated in the nuclei of sarcomere-damaged myofibers. Furthermore, we found that Arpp/Ankrd2 tended to be localized in euchromatin where genes are transcriptionally activated. Based on these findings, we suggest that Arpp/Ankrd2 may translocate from the I-band to the nucleus in response to muscle damage and may participate in the regulation of gene expression.
authors.affiliation: Department of Molecular Pathology, Faculty of Medicine, Oita University, Yufu-city, Oita, 879-5593, Japan. tuka@med.oita-u.ac.jp
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Tsukamoto
authors.forename: Naoki
authors.initials: N
authors.lastname: Hijiya
authors.forename: Shinji
authors.initials: S
authors.lastname: Yano
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Chisato
authors.initials: C
authors.lastname: Nakada
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Uchida
authors.forename: Keiko
authors.initials: K
authors.lastname: Matsuura
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Moriyama
mesh_terms: D000818:Animals; D054715:Cardiotoxins / Q000494:pharmacology; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D004367:Dry Ice / Q000009:adverse effects; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018657:Muscle Fibers, Slow-Twitch / Q000187:drug effects / Q000378:metabolism*; D009124:Muscle Proteins / Q000032:analysis / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000293:injuries* / Q000473:pathology*
chemical_list: C485877:Ankrd2 protein, mouse; D054715:Cardiotoxins; D004367:Dry Ice; D009124:Muscle Proteins