Cell-matrix adhesion controls Golgi organization and function through Arf1 activation in anchorage-dependent cells

Cell adhesion influences multiple cellular processes, including signaling and trafficking. It was already known that adhesion can impact membrane trafficking and Golgi dynamics. However, the specific mechanisms linking adhesion to Golgi organization remain unclear. Prior research has shown that the Golgi complex is dynamic and can respond to cellular cues. Yet, no prior work had resolved how adhesion directly affects Golgi structure. This gap motivated further investigation into adhesion's role in Golgi regulation. The study aims to clarify how adhesion affects Golgi organization. Integrins and their role in adhesion have been previously studied, but their connection to Arf1 activation is newly explored here. This work addresses a key unresolved question in cell adhesion and organelle dynamics.

This study aimed to investigate how cell-matrix adhesion regulates Golgi organization and function. The specific problem addressed is the lack of understanding about how adhesion influences Golgi structure and activity. The motivation is to identify novel regulatory mechanisms linking adhesion to Golgi dynamics. The researchers focused on adhesion-dependent signaling pathways. They examined whether adhesion affects Golgi organization through Arf1 activation. The study also aimed to determine how adhesion influences Golgi function in anchorage-dependent cells. The goal was to uncover a new regulatory pathway involving integrins and Arf1. This work sought to clarify the role of adhesion in Golgi reorganization and its functional consequences.

The researchers used mouse and human fibroblast cells to study adhesion effects on the Golgi. They manipulated adhesion using integrin-blocking antibodies and fibronectin substrates. Golgi organization was assessed using fluorescence microscopy and structural analysis. Arf1 activation was measured using biochemical assays and functional readouts. The role of dynein and ciliobrevin was tested to determine adhesion-dependent regulation. The study compared suspended and adherent cells to observe Golgi changes. Golgi fragmentation was distinguished from disorganization by ER overlap analysis. The experiments tested whether Arf1 activity is necessary for adhesion-dependent Golgi regulation.

Loss of adhesion caused significant Golgi disorganization in fibroblast cells. Re-adhesion via integrins rapidly restored Golgi structure. Integrin-blocking antibodies disrupted Golgi integrity upon re-adhesion. Golgi networks disorganized along microtubules in suspended cells. ER overlap was absent in disorganized Golgi, distinguishing it from fragmentation. Arf1 activation decreased with adhesion loss and recovered with re-adhesion. Constitutively active Arf1 prevented adhesion-dependent Golgi disorganization. Ciliobrevin blocked adhesion-dependent Golgi reorganization. Adhesion-regulated Golgi organization affected cell surface glycosylation. Arf1 activity was shown to control Golgi function in anchorage-dependent cells.

The authors propose that adhesion regulates Golgi organization through Arf1 activation. Integrin-dependent adhesion controls Arf1 activity, which in turn affects Golgi structure. Adhesion-dependent Arf1 activation modulates dynein binding to microtubules. This pathway is distinct from known Golgi fragmentation mechanisms. The study suggests that Golgi disorganization is adhesion-sensitive and reversible. Adhesion-dependent Golgi regulation impacts cell surface glycosylation. Constitutively active Arf1 can override adhesion effects on Golgi disorganization. These findings identify a novel regulatory mechanism linking adhesion to Golgi function.