Human TREX2 components PCID2 and centrin 2, but not ENY2, have distinct functions in protein export and co-localize to the centrosome

Journal Article · Wed Jan 15 04:00:00 EST 2014 · Experimental Cell Research

DOI:https://doi.org/10.1016/J.YEXCR.2013.11.015· OSTI ID:22278247

Cunningham, Corey N.; Schmidt, Casey A.; Schramm, Nathaniel J. ^[1]; Gaylord, Michelle R. ^[2]

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1. Westminster College, Department of Biology, 319 South Market Street, New Wilmington, PA 16172 (United States)
2. Section of Cell and Developmental Biology, Division of Biological Sciences, University of California – San Diego, 9500 Gilman Drive, 0347, La Jolla, CA 92093-0347 (United States)

TREX-2 is a five protein complex, conserved from yeast to humans, involved in linking mRNA transcription and export. The centrin 2 subunit of TREX-2 is also a component of the centrosome and is additionally involved in a distinctly different process of nuclear protein export. While centrin 2 is a known multifunctional protein, the roles of other human TREX-2 complex proteins other than mRNA export are not known. In this study, we found that human TREX-2 member PCID2 but not ENY2 is involved in some of the same cellular processes as those of centrin 2 apart from the classical TREX-2 function. PCID2 is present at the centrosome in a subset of HeLa cells and this localization is centrin 2 dependent. Furthermore, the presence of PCID2 at the centrosome is prevalent throughout the cell cycle as determined by co-staining with cyclins E, A and B. PCID2 but not ENY2 is also involved in protein export. Surprisingly, siRNA knockdown of PCID2 delayed the rate of nuclear protein export, a mechanism distinct from the effects of centrin 2, which when knocked down inhibits export. Finally we showed that co-depletion of centrin 2 and PCID2 leads to blocking rather than delaying nuclear protein export, indicating the dominance of the centrin 2 phenotype. Together these results represent the first discovery of specific novel functions for PCID2 other than mRNA export and suggest that components of the TREX-2 complex serve alternative shared roles in the regulation of nuclear transport and cell cycle progression. - Highlights: • TREX2 complex member PCID2 but not ENY2 localizes to the centrosome in HeLa cells. • Centrin 2 is required for the localization of PCID2 at the centrosome. • PCID2 is found at the centrosome in G1/S at a slightly higher rate than that in G2/M. • PCID2 but not ENY2 delays the rate of nuclear protein export. • Co-depletion of centrin 2 and PCID2 leads to blocking rather than delaying nuclear protein export.

• OSTI ID: 22278247
• Journal Information: Experimental Cell Research, Journal Name: Experimental Cell Research Journal Issue: 2 Vol. 320; ISSN 0014-4827; ISSN ECREAL
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
CELL CYCLE
HELA CELLS
MESSENGER-RNA
PHENOTYPE
PROTEINS
YEASTS