The alpha subunit of Go interacts with promyelocytic leukemia zinc finger protein and modulates its functions

The GTPase domain of Galphao contributes to the functional interaction of Galphao with the promyelocytic leukemia zinc finger protein

“…In our previous study, we identified PLZF as a Gαο-interacting protein and showed that Gαο binds directly to PLZF and promotes its cellular functions [5]. To confirm that these proteins directly interact, we purified the GST fusion proteins of Gαο and PLZF from bacterial lysates for use in co-immunoprecipitation assays.…”

“…Gαο activation augments PLZF's function as a cell growth suppressor and transcriptional repressor [5]. To establish the effects of the Gαο GTPase deletion mutant on cell growth regulation by PLZF, we performed BrdU incorporation assays on 293T cells co-expressing Gαο Q205L or FLAG-GαοΔL2G, a mutant lacking residues 137 to 354 of Gαο, together with HA-PLZF.…”

“…The plasmids pGEX2T-Gαο and pGEX2T-PLZF were respectively used to express the glutathione-S-transferase (GST) fusion proteins of Gαο and PLZF [5].…”

“…The plasmids pcFLAG-PLZF and pcHA-PLZF were respectively used to express FLAG-and HA-tagged PLZF [5].…”

“…However, unlike the α-subunits of Gi proteins, which inhibit adenylyl cyclase and decrease intracellular cyclic AMP levels, the α-subunit of Go (Gαο) has no effect on adenylyl cyclase; its role, other than to act as a reservoir of βγ subunits available for liberation upon receptor activation, is unclear at present. Recently, we identified PLZF as a Gαο-interacting partner [5]. Activated Gαο interacts directly with PLZF and enhances its cellular function as a repressor of transcription and cell growth.…”