GFAP isoforms control intermediate filament network dynamics, cell morphology, and focal adhesions.

ABSTRACT: Glial fibrillary acidic protein (GFAP) is the characteristic intermediate filament (IF) protein in astrocytes. Expression of its main isoforms, GFAP? and GFAP?, varies in astrocytes and astrocytoma implying a potential regulatory role in astrocyte physiology and pathology. An IF-network is a dynamic structure and has been functionally linked to cell motility, proliferation, and morphology. There is a constant exchange of IF-proteins with the network. To study differences in the dynamic properties of GFAP? and GFAP?, we performed fluorescence recovery after photobleaching experiments on astrocytoma cells with fluorescently tagged GFAPs. Here, we show for the first time that the exchange of GFP-GFAP? was significantly slower than the exchange of GFP-GFAP? with the IF-network. Furthermore, a collapsed IF-network, induced by GFAP? expression, led to a further decrease in fluorescence recovery of both GFP-GFAP? and GFP-GFAP?. This altered IF-network also changed cell morphology and the focal adhesion size, but did not alter cell migration or proliferation. Our study provides further insight into the modulation of the dynamic properties and functional consequences of the IF-network composition.

SUBMITTER: Moeton M 

PROVIDER: S-EPMC5043008 | biostudies-other | 2016 Nov

REPOSITORIES: biostudies-other