The nucleus is an integral component of the molecular clutch. Cartoon showing the nucleus as a structurally integrated, force-sensitive component of the molecular clutch model. The molecular clutch model proposes that ECM-bound integrins indirectly couple to actin retrograde flow and actomyosin contractility via force sensitive proteins (e.g., talin and vinculin) and, once engaged, are capable of bridging force between the extracellular environment and the cytoskeleton. An engaged molecular clutch can exert mechanical force on its environment through focal adhesions, giving rise to normal mechanical effort, as indicated by contractile energy and traction stress. The nucleus, though distal to the focal adhesion, is physically integrated with the cytoskeleton via the LINC complex. Enucleation, disruption of the LINC complex, and loss of lamin A/C caused a decrease in the contractile energy, whereas enucleation and disruption of the LINC complex caused a decrease in traction stress. Collectively, these nuclear defects manifest as lower migration velocity on physiologically normal substrata (∼8 kPa) compared with controls. Upon increasing substrata rigidity (8–25 kPa), migration velocity was rescued, suggesting a greater force input was necessary to engage the molecular clutch.