scholarly journals Geranylgeranyl Transferase

2020 ◽  
Author(s):  
2021 ◽  
Vol 22 (15) ◽  
pp. 7907
Author(s):  
Joanna Rojek ◽  
Matthew R. Tucker ◽  
Michał Rychłowski ◽  
Julita Nowakowska ◽  
Małgorzata Gutkowska

Auxin is a key regulator of plant development affecting the formation and maturation of reproductive structures. The apoplastic route of auxin transport engages influx and efflux facilitators from the PIN, AUX and ABCB families. The polar localization of these proteins and constant recycling from the plasma membrane to endosomes is dependent on Rab-mediated vesicular traffic. Rab proteins are anchored to membranes via posttranslational addition of two geranylgeranyl moieties by the Rab Geranylgeranyl Transferase enzyme (RGT), which consists of RGTA, RGTB and REP subunits. Here, we present data showing that seed development in the rgtb1 mutant, with decreased vesicular transport capacity, is disturbed. Both pre- and post-fertilization events are affected, leading to a decrease in seed yield. Pollen tube recognition at the stigma and its guidance to the micropyle is compromised and the seed coat forms incorrectly. Excess auxin in the sporophytic tissues of the ovule in the rgtb1 plants leads to an increased tendency of autonomous endosperm formation in unfertilized ovules and influences embryo development in a maternal sporophytic manner. The results show the importance of vesicular traffic for sexual reproduction in flowering plants, and highlight RGTB1 as a key component of sporophytic-filial signaling.


2013 ◽  
Vol 304 (4) ◽  
pp. L221-L229 ◽  
Author(s):  
Zirak Hasan ◽  
Milladur Rahman ◽  
Karzan Palani ◽  
Ingvar Syk ◽  
Bengt Jeppsson ◽  
...  

Overwhelming accumulation of neutrophils is a significant component in septic lung damage, although the signaling mechanisms behind neutrophil infiltration in the lung remain elusive. In the present study, we hypothesized that geranylgeranylation might regulate the inflammatory response in abdominal sepsis. Male C57BL/6 mice received the geranylgeranyl transferase inhibitor, GGTI-2133, before cecal ligation and puncture (CLP). Bronchoalveolar lavage fluid and lung tissue were harvested for analysis of neutrophil infiltration, as well as edema and CXC chemokine formation. Blood was collected for analysis of Mac-1 on neutrophils and CD40L on platelets. Gene expression of CXC chemokines, tumor necrosis factor-α (TNF-α), and CCL2 chemokine was determined by quantitative RT-PCR in isolated alveolar macrophages. Administration of GGTI-2133 markedly decreased CLP-induced infiltration of neutrophils, edema, and tissue injury in the lung. CLP triggered clear-cut upregulation of Mac-1 on neutrophils. Inhibition of geranylgeranyl transferase reduced CLP-evoked upregulation of Mac-1 on neutrophils in vivo but had no effect on chemokine-induced expression of Mac-1 on isolated neutrophils in vitro. Notably, GGTI-2133 abolished CLP-induced formation of CXC chemokines, TNF-α, and CCL2 in alveolar macrophages in the lung. Geranylgeranyl transferase inhibition had no effect on sepsis-induced platelet shedding of CD40L. In addition, inhibition of geranylgeranyl transferase markedly decreased CXC chemokine-triggered neutrophil chemotaxis in vitro. Taken together, our findings suggest that geranylgeranyl transferase is an important regulator of CXC chemokine production and neutrophil recruitment in the lung. We conclude that inhibition of geranylgeranyl transferase might be a potent way to attenuate acute lung injury in abdominal sepsis.


Blood ◽  
2003 ◽  
Vol 102 (9) ◽  
pp. 3354-3362 ◽  
Author(s):  
Niels W. C. J. van de Donk ◽  
Marloes M. J. Kamphuis ◽  
Berris van Kessel ◽  
Henk M. Lokhorst ◽  
Andries C. Bloem

AbstractHMG-CoA reductase is the rate-limiting enzyme of the mevalonate pathway leading to the formation of cholesterol and isoprenoids such as farnesylpyrophosphate (FPP) and geranylgeranylpyrophosphate (GGPP). The inhibition of HMG-CoA reductase by lovastatin induced apoptosis in plasma cell lines and tumor cells from patients with multiple myeloma. Here we show that cotreatment with mevalonate or geranylgeranyl moieties, but not farnesyl groups, rescued myeloma cells from lovastatin-induced apoptosis. In addition, the inhibition of geranylgeranylation by specific inhibition of geranylgeranyl transferase I (GGTase I) induced the apoptosis of myeloma cells. Apoptosis triggered by the inhibition of geranylgeranylation was associated with reduction of Mcl-1 protein expression, collapse of the mitochondrial transmembrane potential, expression of the mitochondrial membrane protein 7A6, cytochrome c release from mitochondria into the cytosol, and stimulation of caspase-3 activity. These results imply that protein geranylgeranylation is critical for regulating myeloma tumor cell survival, possibly through regulating Mcl-1 expression. Our results show that pharmacologic agents such as lovastatin or GGTase inhibitors may be useful in the treatment of multiple myeloma.


2021 ◽  
Author(s):  
◽  
Kyle Cornelius Van de Bittner

<p>Nature holds some of the greatest secrets in drug design and development and the ability to access these trade secrets has been revolutionised by modern bioengineering technologies. In order to exploit these technologies it is essential to understand what genes are involved in compound production and the enzymatic steps that limit flux to the desired product. This thesis describes the discovery of four secondary-metabolic enzymatic steps involved in the biosynthesis of a group of valuable natural products known as nodulisporic acids. Nodulisporic acids are known for their potent insecticidal activities; however, biosynthesis of these compounds by the natural fungal producer, Hypoxylon pulicicidum (Nodulisporium sp.), is exceptionally difficult and has prevented the commercial development of novel nodulisporic acid-containing veterinary medicines and crop protects. To discover how nodulisporic acids are biosynthesized: 1. the H. pulicicidum genome was sequenced 2. a gene cluster responsible for nodulisporic acid production was predicted 3. genes in the cluster were functionally characterised by pathway reconstitution in a common, fast growing mould, Penicillium paxilli In turn, four genes involved in the biosynthesis of the nodulisporic acid core compound, nodulisporic acid F, have been functionally characterised. The four genes encode a geranylgeranyl transferase (NodC), a flavin adenine dinucleotide-dependent oxygenase (NodM), an indole diterpene cyclase (NodB) and a cytochrome P450 oxygenase (NodW). Two of the gene products (NodM and NodW) catalyse two previously unreported reactions that provide the enzymatic basis of the biosynthetic branch point unique to nodulisporic acid biosynthesis. From here, future efforts will explore how these genes can be engineered to overcome flux bottlenecks and enable production of significantly increased, and even industrially relevant, product titres.</p>


2008 ◽  
Vol 377 (2) ◽  
pp. 453-457 ◽  
Author(s):  
Michelle A. Lawson ◽  
Les Coulton ◽  
Frank H. Ebetino ◽  
Karin Vanderkerken ◽  
Peter I. Croucher

Science ◽  
1993 ◽  
Vol 259 (5093) ◽  
pp. 377-381 ◽  
Author(s):  
M. Seabra ◽  
M. Brown ◽  
J. Goldstein

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Guo-Ping Chen ◽  
Jian Yang ◽  
Guo-Feng Qian ◽  
Wei-Wei Xu ◽  
Xiao-Qin Zhang

The proliferation of vascular smooth muscle cells (VSMCs) induced by oxidative injury is one of the main features in diabetes-accelerated atherosclerosis. Geranylgeranyl transferase-I (GGTase-I) is an essential enzyme mediating posttranslational modification, especially the geranylgeranylation of small GTPase, Rac1. Our previous studies found that GGTase-I played an important role in diabetes-accelerated atherosclerosis. However, its exact role is largely unclear. In this study, mouse conditional knockout of VSMC GGTase-I (Pggt1bΔ/Δ mice) was generated using the CRISPR/Cas9 system. The mouse model of diabetes-accelerated atherosclerosis was induced by streptozotocin injections and an atherogenic diet. We found that GGTase-I knockout attenuated diabetes-accelerated atherosclerosis in vivo and suppressed high-glucose-induced VSMC proliferation in vitro. Moreover, after a 16-week duration of diabetes, Pggt1bΔ/Δ mice exhibited lower α-smooth muscle actin (α-SMA) and nitrotyrosine level, Rac1 activity, p47phox and NOXO1 expression, and phospho-ERK1/2 and phosphor-JNK content than wild-type mice. Meanwhile, the same changes were found in Pggt1bΔ/Δ VSMCs cultured with high glucose (22.2 mM) in vitro. In conclusion, GGTase-I knockout efficiently blocked diabetes-accelerated atherosclerosis, and this protective effect must be related to the inhibition of VSMC proliferation. The potential mechanisms probably involved interfering Rac1 geranylgeranylation, inhibiting the assembly of NADPH oxidase cytosolic regulatory subunits, reducing oxidative injury, and decreasing ERK1/2 and JNK phosphorylation.


2016 ◽  
Vol 113 (39) ◽  
pp. 11040-11045 ◽  
Author(s):  
Ping Che ◽  
Zuo-Yu Zhao ◽  
Kimberly Glassman ◽  
David Dolde ◽  
Tiger X. Hu ◽  
...  

Micronutrient deficiencies are common in locales where people must rely upon sorghum as their staple diet. Sorghum grain is seriously deficient in provitamin A (β-carotene) and in the bioavailability of iron and zinc. Biofortification is a process to improve crops for one or more micronutrient deficiencies. We have developed sorghum with increased β-carotene accumulation that will alleviate vitamin A deficiency among people who rely on sorghum as their dietary staple. However, subsequent β-carotene instability during storage negatively affects the full utilization of this essential micronutrient. We determined that oxidation is the main factor causing β-carotene degradation under ambient conditions. We further demonstrated that coexpression of homogentisate geranylgeranyl transferase (HGGT), stacked with carotenoid biosynthesis genes, can mitigate β-carotene oxidative degradation, resulting in increased β-carotene accumulation and stability. A kinetic study of β-carotene degradation showed that the half-life of β-carotene is extended from less than 4 wk to 10 wk on average with HGGT coexpression.


1994 ◽  
Vol 91 (25) ◽  
pp. 11963-11967 ◽  
Author(s):  
C. C. Farnsworth ◽  
M. C. Seabra ◽  
L. H. Ericsson ◽  
M. H. Gelb ◽  
J. A. Glomset

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