Human Drg1 is a potassium‐dependent GTPase enhanced by Lerepo4

Abstract

Human Drg1, a guanine nucleotide binding protein conserved in archaea and eukaryotes, is regulated by Lerepo4. Together they form a complex which interacts with translating ribosomes. Here we have purified and characterized the GTPase activity of Drg1 and three variants, a shortened mutant depleted of the TGS domain, a phosphomimicking mutant and a construct with the two combined mutations. Our data reveal that potassium strongly stimulates the GTPase activity, without changing the monomeric status of Drg1 and that this activity is notably reduced in the mutants. The nature of Lerepo4 association has also been investigated. Dissecting the role of the different domains revealed that Dfrp domain is the sole responsible for the Drg1 increase in thermal stability and the four fold stimulation over its catalytic activity. Lerepo4 action leaves Drg1 affinity for nucleotides unaffected, feasibly favoring a switch I reorientation, mainly via the TGS domain. Drg1 displayed a high temperature optimum of activity at 42°C, suggesting the ability of being active under possible heat stress conditions. Structured digital abstract Drg1 and Drg1 bind by molecular sieving (View Interaction: 1, 2)

Developmentally Regulated GTP binding protein 1 (DRG1) controls microtubule dynamics

“…This faster recovery can be either explained by the polymerization activity of DRG1 or by the stabilization activity, which might stabilize small microtubule remnants that regrow faster afterwards when cells were provided with fresh, warm medium. It was observed before that DRG1 shows some thermophilic behavior: DRG1 hydrolyzes GTP over a wide range of temperatures with an optimum at 42 °C 23 . Maybe DRG1 is also more active at cold temperatures compared to other proteins or performs its functions mainly under extreme, stress-situations.…”

“…The crystal structure of the yeast DRG1 homolog, Rbg1 (Ribosome binding GTPase 1), together with a C-terminal fragment of the yeast homolog of DFRP1 (Tma46), shows that the canonical G-domain of the DRGs is interrupted by another domain, the S5D2L domain 20 . DRG1 seems to have an intrinsic GTPase activity that does not necessarily need a GTPase activating protein as is usually the case for most small GTPases 16 , 20 , 23 . Potassium ions stimulate this activity as well as DFRP1 binding.…”

Age-specific changes in genome-wide methylation enrich for Foxa2 and estrogen receptor alpha binding sites

“…Mouse chromosome 11 has previously been implicated in premature death, infertility, runting and neurological defects[ 54 ]. Nearby genes on chromosome 11 with hypermethylation at transcription start sites were Sfi1 , which is a spindle protein important for mitosis and organelle biogenesis[ 55 ] and Drg1 [developmentally regulated GTP-binding protein 1], which is a highly conserved gene important for development and regulating cell growth and acts as a tumor suppressor[ 56 ]. The specific hypermethylation of TSSs at these two genes could point to age-related transcriptional repression of these two important genes involved in cell division and energy production, respectively.…”

DRG1 is a potential oncogene in lung adenocarcinoma and promotes tumor progression via spindle checkpoint signaling regulation

“…DRG1 is the SUMOylation substrate of UBC9 [22]. Otherwise, mimicking phosphorylation of Thr100 decreases DRG1 activity [28]. DRG1 is subjected to a tight regulation, and it will be interesting to investigate whether SUMOylation, phosphorylation and DRG1 GTPase activity is critical for its mitosis regulation.…”