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A novel interaction of the Golgi complex with the vimentin intermediate filament cytoskeleton.

Gao Y, Sztul E - J. Cell Biol. (2001)

Bottom Line: We show that the peripherally associated Golgi protein FTCD binds directly to vimentin subunits and to polymerized vimentin filaments in vivo and in vitro.Formation of the FTCD fibers is obligatorily coupled to vimentin assembly and does not occur in vim(-/-) cells.The FTCD-mediated regulation of vimentin IF is not a secondary effect of changes in the microtubule or the actin cytoskeletons, since those cytoskeletal systems appear unaffected by FTCD expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.

ABSTRACT
The integration of the vimentin intermediate filament (IF) cytoskeleton and cellular organelles in vivo is an incompletely understood process, and the identities of proteins participating in such events are largely unknown. Here, we show that the Golgi complex interacts with the vimentin IF cytoskeleton, and that the Golgi protein formiminotransferase cyclodeaminase (FTCD) participates in this interaction. We show that the peripherally associated Golgi protein FTCD binds directly to vimentin subunits and to polymerized vimentin filaments in vivo and in vitro. Expression of FTCD in cultured cells results in the formation of extensive FTCD-containing fibers originating from the Golgi region, and is paralleled by a dramatic rearrangements of the vimentin IF cytoskeleton in a coordinate process in which vimentin filaments and FTCD integrate into chimeric fibers. Formation of the FTCD fibers is obligatorily coupled to vimentin assembly and does not occur in vim(-/-) cells. The FTCD-mediated regulation of vimentin IF is not a secondary effect of changes in the microtubule or the actin cytoskeletons, since those cytoskeletal systems appear unaffected by FTCD expression. The assembly of the FTCD/vimentin fibers causes a coordinate change in the structure of the Golgi complex and results in Golgi fragmentation into individual elements that are tethered to the FTCD/vimentin fibers. The observed interaction of Golgi elements with vimentin filaments and the ability of FTCD to specifically interacts with both Golgi membrane and vimentin filaments and promote their association suggest that FTCD might be a candidate protein integrating the Golgi compartment with the IF cytoskeleton.

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Golgi elements interact with vimentin filaments in vivo. (A) MFT-6 cells were labeled with polyclonal anti-GM130 and monoclonal antivimentin antibodies. Extended Golgi elements align with vimentin filaments (arrowheads). (B) MFT-6 cells were treated with 10 μg/ml nocodazole for 5 h at 37°C before labeling as in A. The Golgi complex was disrupted into Golgi ministacks, but the Golgi ministacks were associated with vimentin filaments (arrowheads). Arrow points to a mass of collapsed vimentin. (C) NRK cells were treated with 10 μg/ml nocodazole for 5 h at 37°C and then labeled with polyclonal anti-GM130 and monoclonal anti-FTCD antibodies. FTCD colocalizes with GM130 in Golgi ministacks (arrowheads).
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Figure 7: Golgi elements interact with vimentin filaments in vivo. (A) MFT-6 cells were labeled with polyclonal anti-GM130 and monoclonal antivimentin antibodies. Extended Golgi elements align with vimentin filaments (arrowheads). (B) MFT-6 cells were treated with 10 μg/ml nocodazole for 5 h at 37°C before labeling as in A. The Golgi complex was disrupted into Golgi ministacks, but the Golgi ministacks were associated with vimentin filaments (arrowheads). Arrow points to a mass of collapsed vimentin. (C) NRK cells were treated with 10 μg/ml nocodazole for 5 h at 37°C and then labeled with polyclonal anti-GM130 and monoclonal anti-FTCD antibodies. FTCD colocalizes with GM130 in Golgi ministacks (arrowheads).

Mentions: To test whether Golgi elements and vimentin filaments associate in vivo, we examined mouse MFT-6 cells processed for double label immunofluorescence to detect the Golgi protein GM130 and vimentin. As shown in Fig. 7 A, MFT-6 cells have relatively large and extended Golgi complexes, with individual Golgi elements often colocalizing with vimentin IFs (arrowheads). Careful examination of distinct focal planes indicated that the majority of Golgi ribbons are closely aligned and parallel the vimentin filaments. Analogous images were observed in COS-7, NRK, and HeLa cells (data not shown), showing the generality of the Golgi–vimentin IFs association.


A novel interaction of the Golgi complex with the vimentin intermediate filament cytoskeleton.

Gao Y, Sztul E - J. Cell Biol. (2001)

Golgi elements interact with vimentin filaments in vivo. (A) MFT-6 cells were labeled with polyclonal anti-GM130 and monoclonal antivimentin antibodies. Extended Golgi elements align with vimentin filaments (arrowheads). (B) MFT-6 cells were treated with 10 μg/ml nocodazole for 5 h at 37°C before labeling as in A. The Golgi complex was disrupted into Golgi ministacks, but the Golgi ministacks were associated with vimentin filaments (arrowheads). Arrow points to a mass of collapsed vimentin. (C) NRK cells were treated with 10 μg/ml nocodazole for 5 h at 37°C and then labeled with polyclonal anti-GM130 and monoclonal anti-FTCD antibodies. FTCD colocalizes with GM130 in Golgi ministacks (arrowheads).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2198822&req=5

Figure 7: Golgi elements interact with vimentin filaments in vivo. (A) MFT-6 cells were labeled with polyclonal anti-GM130 and monoclonal antivimentin antibodies. Extended Golgi elements align with vimentin filaments (arrowheads). (B) MFT-6 cells were treated with 10 μg/ml nocodazole for 5 h at 37°C before labeling as in A. The Golgi complex was disrupted into Golgi ministacks, but the Golgi ministacks were associated with vimentin filaments (arrowheads). Arrow points to a mass of collapsed vimentin. (C) NRK cells were treated with 10 μg/ml nocodazole for 5 h at 37°C and then labeled with polyclonal anti-GM130 and monoclonal anti-FTCD antibodies. FTCD colocalizes with GM130 in Golgi ministacks (arrowheads).
Mentions: To test whether Golgi elements and vimentin filaments associate in vivo, we examined mouse MFT-6 cells processed for double label immunofluorescence to detect the Golgi protein GM130 and vimentin. As shown in Fig. 7 A, MFT-6 cells have relatively large and extended Golgi complexes, with individual Golgi elements often colocalizing with vimentin IFs (arrowheads). Careful examination of distinct focal planes indicated that the majority of Golgi ribbons are closely aligned and parallel the vimentin filaments. Analogous images were observed in COS-7, NRK, and HeLa cells (data not shown), showing the generality of the Golgi–vimentin IFs association.

Bottom Line: We show that the peripherally associated Golgi protein FTCD binds directly to vimentin subunits and to polymerized vimentin filaments in vivo and in vitro.Formation of the FTCD fibers is obligatorily coupled to vimentin assembly and does not occur in vim(-/-) cells.The FTCD-mediated regulation of vimentin IF is not a secondary effect of changes in the microtubule or the actin cytoskeletons, since those cytoskeletal systems appear unaffected by FTCD expression.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.

ABSTRACT
The integration of the vimentin intermediate filament (IF) cytoskeleton and cellular organelles in vivo is an incompletely understood process, and the identities of proteins participating in such events are largely unknown. Here, we show that the Golgi complex interacts with the vimentin IF cytoskeleton, and that the Golgi protein formiminotransferase cyclodeaminase (FTCD) participates in this interaction. We show that the peripherally associated Golgi protein FTCD binds directly to vimentin subunits and to polymerized vimentin filaments in vivo and in vitro. Expression of FTCD in cultured cells results in the formation of extensive FTCD-containing fibers originating from the Golgi region, and is paralleled by a dramatic rearrangements of the vimentin IF cytoskeleton in a coordinate process in which vimentin filaments and FTCD integrate into chimeric fibers. Formation of the FTCD fibers is obligatorily coupled to vimentin assembly and does not occur in vim(-/-) cells. The FTCD-mediated regulation of vimentin IF is not a secondary effect of changes in the microtubule or the actin cytoskeletons, since those cytoskeletal systems appear unaffected by FTCD expression. The assembly of the FTCD/vimentin fibers causes a coordinate change in the structure of the Golgi complex and results in Golgi fragmentation into individual elements that are tethered to the FTCD/vimentin fibers. The observed interaction of Golgi elements with vimentin filaments and the ability of FTCD to specifically interacts with both Golgi membrane and vimentin filaments and promote their association suggest that FTCD might be a candidate protein integrating the Golgi compartment with the IF cytoskeleton.

Show MeSH
Related in: MedlinePlus