adp-ribosylation factor 6 expression and activation are reduced in myometrium in complicated pregnanciesadp-ribosylation因子6表达和激活减少妊娠子宫肌层的复杂.pdfVIP

ADP-Ribosylation Factor 6 Expression and Activation Are Reduced in Myometrium in Complicated Pregnancies 1 1 2¤ ´ ´ 2 Venkateswarlu Kanamarlapudi *, Sian E. Owens , Jon Lartey , Andres Lopez Bernal * 1 Institute of Life Science, College of Medicine, Swansea University, Swansea, United Kingdom, 2 Division of Obstetrics and Gynaecology, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom Abstract Background: ARF6 (ADP-ribosylation factor 6) small GTP binding protein plays critical roles in actin cytoskeleton rearrangements and membrane trafficking, including internalisation of G protein coupled receptors (GPCR). ARF6 operates by cycling between GDP-bound (inactive) and GTP-bound (active) forms and is a potential regulator of GPCR-mediated uterine activity during pregnancy and labour. ARF6 contains very low intrinsic GTP binding activity and depends on GEFs (guanine nucleotide exchange factors) such as CYTH3 (cytohesin 3) to bind GTP. ARF6 and CYTH3 were originally cloned from human placenta, but there is no information on their expression in other reproductive tissues. Methods: The expression of ARF6, ARF1, and CYTH1-4 was investigated by measuring mRNA (using RT-PCR) and protein levels (using immunoblotting) in samples of myometrium obtained from non-pregnant women, and women with normal pregnancies, before or after the spontaneous onset of labour. We also analysed myometrial samples from women with spontaneous preterm labour and from women with complicated pregnancies requiring emergency preterm delivery. The GST)-effector pull down assay was used to study the presence of active ARF6 and ARF1 in all myometrial extracts.