Ligand-Modulated Cross-Bridging of Microtubules by Phosphofructokinase

Lehotzky, Attila; Pálfia, Zsolt; Kovács, János; Molnár, Anikó; Ovádi, Judit

doi:10.1006/bbrc.1994.2499

Cited by 27 publications

(40 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our results indicated a wider distribution of PFK than CAV-1 within the VSM cell, regard- less of phenotype. The wider distribution of PFK fluorescence in this study is consistent with considerable evidence that suggests that glycolytic enzymes are found not only in association with the plasma membrane (11,18,21,35,44,45) but also may be in association with the microtubules (16,26,28,29,53,62,63) and F-actin (3,25,27), resulting in different glycolytic cascades associated to different cellular domains. Presumably, a similar distribution of one pool of PFK with CAV-1 may provide the structural basis for one compartment of glycolysis from other metabolic pathways.…”

Section: Metabolic Compartmentation In Vsm Cells and The Role Of The supporting

confidence: 90%

Metabolic organization in vascular smooth muscle: distribution and localization of caveolin-1 and phosphofructokinase

Vallejo

Hardin

2004

American Journal of Physiology-Cell Physiology

View full text Add to dashboard Cite

We have shown that a compartmentation of glycolysis and gluconeogenesis exists in vascular smooth muscle (VSM) and that an intact plasma membrane is essential for compartmentation. Previously, we observed that disruption of the caveolae inhibited glycolysis but stimulated gluconeogenesis, suggesting a link between caveolae and glycolysis. We hypothesized that glycolytic enzymes specifically localize to caveolae. We used confocal microscopy to determine the localization of caveolin-1 (CAV-1) and phosphofructokinase (PFK) in freshly isolated VSM cells and cultured A7r5 cells. Freshly isolated cells exhibited a peripheral (membrane) localization of CAV-1 with 85.3% overlap with PFK. However, only 59.9% of PFK was localized with CAV-1, indicating a wider distribution of PFK than CAV-1. A7r5 cells exhibited compartmentation of glycolysis and gluconeogenesis and displayed two apparent phenotypes distinguishable by shape (spindle and ovoid shaped). In both phenotypes, CAV-1 fluorescence overlapped with PFK fluorescence (83.1 and 81.5%, respectively). However, the overlap of PFK with CAV-1 was lower in the ovoid-shaped (35.9%) than the spindle-shaped cells (53.7%). There was also a progressive shift in pattern of colocalization from primarily the membrane in spindle-shaped cells (both freshly isolated and cultured cells) to primarily the cytoplasm in ovoid-shaped cells. Overall, cellular colocalization of PFK with CAV-1 was significant in all cell types (0.68 ≥ R2 ≤ 0.77). Coimmunoprecipitation of PFK with CAV-1 further validated the possible interaction between the proteins. We conclude that a similar distribution of one pool of PFK with CAV-1 contributes to the compartmentation of glycolysis from gluconeogenesis.

show abstract

Section: Metabolic Compartmentation In Vsm Cells and The Role Of The supporting

confidence: 90%

Metabolic organization in vascular smooth muscle: distribution and localization of caveolin-1 and phosphofructokinase

Vallejo

Hardin

2004

American Journal of Physiology-Cell Physiology

View full text Add to dashboard Cite

show abstract

“…The effects of KAR-3 and KAR-4 on tubulin polymerization were similar to that of KAR-2, both in the absence and presence of PFK (data not shown). These results are similar to those obtained with vinblastine (Lehotzky et al, 1994), however the resistance of bundled microtubules was higher when KARderivatives were used.…”

Section: Selectivity Of Antimicrotubular Activitysupporting

confidence: 88%

“…A common feature of the samples is that they contain many C-shaped aggregates that probably represent tubulin ligomers. However, no such profiles were seen in samples assembled in the presence of PFK without addition of drugs (Lehotzky et al, 1994).…”

Section: Selectivity Of Antimicrotubular Activitymentioning

confidence: 90%

“…Then the samples were centrifuged at 100 000 g for 20 min at 30°C. Under these conditions, microtubules and microtubule-bound PFK are completely pelleted, whereas non-microtubule-bound (uncomplexed) PFK and non-polymerized tubulin dimers remain in the supernatant (Lehotzky et al, 1993(Lehotzky et al, , 1994Vértessy et al, 1996). The protein amount in the pellet and supernatant fractions was quantified by densitometry after SDS-PAGE separation in 9% polyacrylamide gels using the BioRad GelDoc 1000 densitometer with the Molecular Analyst software (Vértessy et al, 1996(Vértessy et al, , 1997.…”

Section: Pelleting Experimentsmentioning

confidence: 99%

“…The bundling activity of PFK was previously demonstrated in vitro (Lehotzky et al, 1994). The concentration of drugs (2 µM) was selected to inhibit significantly the tubulin polymerization in the absence of PFK (cf.…”

Section: Selectivity Of Antimicrotubular Activitymentioning

confidence: 99%

See 2 more Smart Citations

New semisynthetic vinca alkaloids: chemical, biochemical and cellular studies

et al. 1999

View full text Add to dashboard Cite

Summary A new semisynthetic anti-tumour bis-indol compound, KAR-2 [3′-(β-chloroethyl)-2′,4′-dioxo-3,5′-spiro-oxazolidino-4-deacetoxyvinblastine] with lower toxicity than vinca alkaloids used in chemotherapy binds to calmodulin but, in contrast to vinblastine, does not exhibit anti-calmodulin activity. To investigate whether the modest chemical modification of bis-indol structure is responsible for the lack of anticalmodulin potency and for the different pharmacological effects, new derivatives have been synthesized for comparative studies. The synthesis of the KAR derivatives are presented. The comparative studies showed that the spiro-oxazolidino ring and the substitution of a formyl group to a methyl one were responsible for the lack of anti-calmodulin activities. The new derivatives, similar to the mother compounds, inhibited the tubulin assembly in polymerization tests in vitro, however their inhibitory effect was highly dependent on the organization state of microtubules; bundled microtubules appeared to be resistant against the drugs. The maximal cytotoxic activities of KAR derivatives in in vivo mice hosting leukaemia P388 or Ehrlich ascites tumour cells appeared similar to that of vinblastine or vincristine, however significant prolongation of life span could be reached with KAR derivatives only after the administration of a single dose. These studies plus data obtained using a cultured human neuroblastoma cell line showed that KAR compounds displayed their cytotoxic activities at significantly higher concentrations than the mother compounds, although their antimicrotubular activities were similar in vitro. These data suggest that vinblastine/vincristine damage additional crucial cell functions, one of which could be related to calmodulin-mediated processes.

show abstract

Phosphofructokinases

Ou��di

2002

Wiley Encyclopedia of Molecular Medicine

View full text Add to dashboard Cite

Ligand-Modulated Cross-Bridging of Microtubules by Phosphofructokinase

Cited by 27 publications

References 0 publications

Metabolic organization in vascular smooth muscle: distribution and localization of caveolin-1 and phosphofructokinase

Metabolic organization in vascular smooth muscle: distribution and localization of caveolin-1 and phosphofructokinase

New semisynthetic vinca alkaloids: chemical, biochemical and cellular studies

Phosphofructokinases

Contact Info

Product

Resources

About