TY - JOUR
T1 - Subcellular distribution of human RDM1 protein isoforms and their nucleolar accumulation in response to heat shock and proteotoxic stress
AU - Messaoudi, Lydia
AU - Yang, Yun Gui
AU - Kinomura, Aiko
AU - Stavreva, Diana A.
AU - Yan, Gonghong
AU - Bortolin-Cavaillé, Larie Line
AU - Arakawa, Hiroshi
AU - Buerstedde, Jean Marie
AU - Hainaut, Pierre
AU - Cavaillé, Jérome
AU - Takata, Minoru
AU - Van Dyck, Eric
N1 - Funding Information:
This study was funded by La Ligue contre le Cancer, Comitédu Rhône, France; Association pour la Recherche sur le Cancer, France. We are very grateful to Dr Young-Tae Chang (New York University) for his generous gift of the RNA-dye F22, Dr Yaron Shav-Tal (Bar Ilan University) for his comments on our analysis of nucleolar caps and Marie Béatrice Secretan for her contribution during the early phase of this project. We thank Bakary Sylla and Birke Bartosch for critically reading the manuscript and Georges Mollon and Roland Dray for assistance during preparation of the Figures. Funding to pay the Open Access publication charges for this article was provided by the IARC regular budget.
PY - 2007/10
Y1 - 2007/10
N2 - The RDM1 gene encodes a RNA recognition motif (RRM)-containing protein involved in the cellular response to the anti-cancer drug cisplatin in vertebrates. We previously reported a cDNA encoding the full-length human RDM1 protein. Here, we describe the identification of 11 human cDNAs encoding RDM1 protein isoforms. This repertoire is generated by alternative pre-mRNA splicing and differential usage of two translational start sites, resulting in proteins with long or short N-terminus and a great diversity in the exonic composition of their C-terminus. By using tagged proteins and fluorescent microscopy, we examined the subcellular distribution of full-length RDM1 (renamed RDM1α), and other RDM1 isoforms. We show that RDM1α undergoes subcellular redistribution and nucleolar accumulation in response to proteotoxic stress and mild heat shock. In unstressed cells, the long N-terminal isoforms displayed distinct subcellular distribution patterns, ranging from a predominantly cytoplasmic to almost exclusive nuclear localization, suggesting functional differences among the RDM1 proteins. However, all isoforms underwent stress-induced nucleolar accumulation. We identified nuclear and nucleolar localization determinants as well as domains conferring cytoplasmic retention to the RDM1 proteins. Finally, RDM1 null chicken DT40 cells displayed an increased sensitivity to heat shock, compared to wild-type (wt) cells, suggesting a function for RDM1 in the heat-shock response.
AB - The RDM1 gene encodes a RNA recognition motif (RRM)-containing protein involved in the cellular response to the anti-cancer drug cisplatin in vertebrates. We previously reported a cDNA encoding the full-length human RDM1 protein. Here, we describe the identification of 11 human cDNAs encoding RDM1 protein isoforms. This repertoire is generated by alternative pre-mRNA splicing and differential usage of two translational start sites, resulting in proteins with long or short N-terminus and a great diversity in the exonic composition of their C-terminus. By using tagged proteins and fluorescent microscopy, we examined the subcellular distribution of full-length RDM1 (renamed RDM1α), and other RDM1 isoforms. We show that RDM1α undergoes subcellular redistribution and nucleolar accumulation in response to proteotoxic stress and mild heat shock. In unstressed cells, the long N-terminal isoforms displayed distinct subcellular distribution patterns, ranging from a predominantly cytoplasmic to almost exclusive nuclear localization, suggesting functional differences among the RDM1 proteins. However, all isoforms underwent stress-induced nucleolar accumulation. We identified nuclear and nucleolar localization determinants as well as domains conferring cytoplasmic retention to the RDM1 proteins. Finally, RDM1 null chicken DT40 cells displayed an increased sensitivity to heat shock, compared to wild-type (wt) cells, suggesting a function for RDM1 in the heat-shock response.
UR - http://www.scopus.com/inward/record.url?scp=36148989178&partnerID=8YFLogxK
U2 - 10.1093/nar/gkm753
DO - 10.1093/nar/gkm753
M3 - Article
C2 - 17905820
AN - SCOPUS:36148989178
SN - 0305-1048
VL - 35
SP - 6571
EP - 6587
JO - Nucleic Acids Research
JF - Nucleic Acids Research
IS - 19
ER -