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Phospholipase Cβ1 is linked to RNA interference of specific genes through translin‐associated factor X
Author(s) -
Philip Finly,
Guo Yuanjian,
Aisiku Omoz,
Scarlata Suzanne
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.12-213934
Subject(s) - hek 293 cells , gene knockdown , gene silencing , rna interference , hela , biology , small interfering rna , microbiology and biotechnology , cell , rna , gene , biochemistry
Phospholipase Cβ1 (PLCβ1) is a G‐protein‐regulated enzyme whose activity results in proliferative and mitogenic changes in the cell. We have previously found that in solution PLCβ1 binds to the RNA processing protein translin‐associated factor X (TRAX) with nanomolar affinity and that this binding competes with G proteins. Here, we show that endogenous PLCβ1 and TRAX interact in SK‐N‐SH cells and also in HEK293 cells induced to overexpress PLCβ1. In HEK293 cells, TRAX overexpression ablates Ca 2+ signals generated by G protein‐PLCβ1 activation. TRAX plays a key role in down‐regulation of proteins by small, interfering RNA, and PLCβ1 overexpression completely reverses the 2‐ to 4‐fold down‐regulation of GAPDH by siRNA in HEK293 and HeLa cells as seen by an ~4‐fold recovery in both the transcript and protein levels. Also, down‐regulation of endogenous PLCβ1 in HEK293 and HeLa cells allows for an ~20% increase in siRNA(GAPDH) silencing. While PLCβ1 overexpression results in a 50% reversal of cell death caused by siRNA(LDH), it does not affect cell survival or silencing of other genes ( e.g. , cyclophilin, Hsp90, translin). PLCβ1 overexpression in HEK293 and HeLa cells causes a 30% reduction in the total amount of small RNAs. LDH and GAPDH are part of a complex that promotes H2B synthesis that allows cells to progress through the S phase. We find that PLCβ1 reverses the cell death and completely rescues H2B levels caused by siRNA knockdown of LDH or GAPDH. Taken together, our study shows a novel role of PLCβ1 in gene regulation through TRAX association.—Philip, F., Guo, Y., Aisiku, O., Scarlata, S. Phospholipase Cβ1 is linked to RNA interference of specific genes through translin‐associated factor X. FASEB J. 26, 4903–4913 (2012). www.fasebj.org