The human "protein interacting with carboxyl terminus 1" (PICT-1), also designated as the "glioma tumor suppressor candidate region 2 gene product", GLTSCR2, is a nucleolar protein whose activity is, as yet, unknown. Contradictory results regarding the role of PICT-1 in cancer have been reported, and PICT-1 has been suggested to function either as a tumor suppressor protein or as an oncogene. In this study, we demonstrate self-association of PICT-1. Through yeast two-hybrid assay, we identified PICT-1 as its own interaction partner. We confirmed the interaction of PICT-1 with itself by direct yeast two-hybrid assay and also showed self-association of PICT-1 in mammalian cells by co-immunoprecipitation and fluorescence resonance energy transfer assays. Furthermore, we confirmed direct self-association of PICT-1 by using in vitro microfluidic affinity binding assays. The later assay also identified the carboxy-terminal domain as mediating self-interaction of PICT-1. Glutaraldehyde cross-linking and gel-filtration assays suggest that PICT-1 forms dimers, though it may form higher-order complexes as well. Our findings add another layer of complexity in understanding the different functions of PICT-1 and may help provide insights regarding the activities of this protein.
|Number of pages||16|
|Journal||Journal of Molecular Biology|
|State||Published - 12 Jun 2014|
Bibliographical noteFunding Information:
We gratefully acknowledge Prof. Bernard Roizman, Dr. Jordan Chill and Dr. Yarden Opatowsky for reagents, helpful discussions and technical help. Portions of this work submitted by T.B.-S. to Bar Ilan University, Ramat Gan, Israel, are in partial fulfillment of the requirements for the degree of Doctor of Philosophy. The anti-myc developed by Prof. J. M. Bishop was obtained from the Developmental Studies Hybridoma Bank developed under the auspices of the Eunice Kennedy Shriver National Institute of Child Health and Human Development and maintained by The University of Iowa, Department of Biology, Iowa City, IA, USA. This work was supported by grants from the Israel Cancer Association , the Chief Scientist's Office of the Ministry of Health, Israel , and the Israel Science Foundation (Grant No. 709/10 ).
- glioma tumor suppressor candidate region 2 gene product, GLTSCR2
- protein interacting with carboxyl terminus 1, PICT-1