Open AccessHsp40 regulates the amount of keratin proteins via ubiquitin-proteasome pathway in cultured human cells
Author(s) -
Yohtaro Katagata
Publication year - 2011
Publication title -
international journal of molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.048
H-Index - 90
eISSN - 1791-244X
pISSN - 1107-3756
DOI - 10.3892/ijmm.2011.826
Subject(s) - keratin , hacat , proteasome , immunoprecipitation , keratin 8 , biology , microbiology and biotechnology , heat shock protein , gene knockdown , ubiquitin , keratin 5 , cell , gene , cell culture , biochemistry , genetics
Keratins represent important structural components of intermediate filamentproteins. Their expression profiles are remarkably tissue-specific. Recent datahave shown that keratins associate with many proteins including heat shock proteins(HSP). We recently identified cell-specific keratin and HSP expression. We aimedto gain further insight into the regulation of keratins by specific inhibitionthrough knockdown of Hsp40 in human keratinocyte cells. Keratin-HSP interactionin HaCaT cell lysate was evaluated by immunoprecipitation followed by Westernblotting. Immunofluorescence, was used to examine the co-localization of keratinsand Hsp40. Hsp40 depletion led to an increase in the levels of keratin proteins(K5, K14, K10) and a decrease in keratin ubiquitination without influencing keratingene expression. Our results demonstrate direct or indirectly association of Hsp40and imply that expressed keratin proteins were regulated by Hsp40 depending onthe ubiquitin-proteasome pathway in HaCaT. Furthermore, the K10 differentiationmarker was increased by knockdown of Hsp40. The results presented in this studyindicate that Hsp40 is related to the differentiation exchange of keratin pairs.