RESUMEN
NIP-SNAP-1 and -2 are ubiquitous proteins thought to be associated with maintenance of mitochondrial function, neuronal transmission, and autophagy. However, their physiological functions remain largely unknown. To elucidate their functional importance, we screened for proteins that interact with NIP-SNAP-1 and -2, resulting in identification of HSP60 and P62/SQSTM1 as binding proteins. NIP-SNAP-1 and -2 localized in the mitochondrial inner membrane space, whereas HSP60 localized in the matrix. Native gel electrophoresis and filter trap assays revealed that human HSP60 prevented aggregation of newly synthesized NIP-SNAP-2 in an in vitro translation system. Moreover, expression levels of NIP-SNAP-1 and -2 in cells were decreased by knockdown of HSP60, but not HSP10. These findings indicate that HSP60 promotes folding and maintains the stability of NIP-SNAP-1 and -2.
Asunto(s)
Chaperonina 60/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Mitocondriales/metabolismo , Fosfoproteínas/metabolismo , Proteínas/metabolismo , Línea Celular , Chaperonina 10/antagonistas & inhibidores , Chaperonina 10/genética , Chaperonina 10/metabolismo , Chaperonina 60/antagonistas & inhibidores , Chaperonina 60/genética , Técnicas de Silenciamiento del Gen , Humanos , Péptidos y Proteínas de Señalización Intercelular , Péptidos y Proteínas de Señalización Intracelular , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Membranas Mitocondriales/metabolismo , Proteínas Mitocondriales/antagonistas & inhibidores , Proteínas Mitocondriales/química , Proteínas Mitocondriales/genética , Fosfoproteínas/química , Fosfoproteínas/genética , Unión Proteica , Pliegue de Proteína , Mapas de Interacción de Proteínas , Estabilidad Proteica , Proteínas/química , Proteínas/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteína Sequestosoma-1/metabolismoRESUMEN
We studied 242 inpatients--men (34%) and women (66%) reporting vertigo and dizziness while hospitalized at Hakodate Municipal Hospital from July 1999 to June 2002. Adults over 65 years old accounted for 47.3% of all subjects. Reports of symptoms tended to increase in March, August, and December. Cases were classified into 4 groups: 1) peripheral disorders (35.7%), 2) central disorders (7.9%), 3) disorders of other origins (8.3%), and 4) disorders of unknown origin (47.1%). Group 1) involved vestibular neuritis (10.1% of all cases), Meniere diseases (12.4%), benign paroxysmal positional vertigo (BPPV) (5.8%), and sudden deafness with vertigo (5.8%). Patients with vestibular neuritis--25 subjects including men (68%) and women (32%)--tended to be admitted mainly in July. Vestibular compensation in 15 patients with vestibular neuritis was studied using the platform stabilometry. The total length of a locus and the area of surroundings with open eyes decreased significantly (p < 0.05) as the condition of patients improved. In conclusion, many subjects reporting vertigo and dizziness had vestibular neuritis and few had BPPV. We found platform stabilometry to be useful in estimation of improvement in patients with vestibular neuritis.