AT14A has a small domain that has sequence similarities to integrins from animals.Because theexact role of AT14A in cell wall-plasma membrane-cytoskeleton continuum is unknown,wedescribed Arabidopsis thaliana AT14A,which is a member of a family of transmembranereceptors for cell-adhesion molecules in plants.The mutant Arabidopsis at14a cells exhibitvarious growth phenotypes with loss of polarity.Using an AT14A-green fluorescent protein (GFP)fusion that complemented the phenotype conferred by the at14a mutant,we investigated thedistribution of AT14A in suspending cells.Transcripts of AT14A are found in Arabidopsis cellsexamined,AT14A localizes to the plasma membrane.Using immunofluorescence,corticalmicrotubule arrays were significantly altered in cells either overexpressing AT14A or where it hadbeen absented by null mutant.The cortical microtubules were more sensitive to treatment withosmotic stress when AT14A was overexpressed,but more resistant when AT14A was eliminated inmutant cells.It is concluded that AT14A may be an important middle member of the cellwall-plasma membrane-cytoskeleton continuum and play a role in the continuum by regulatingcell wall and cortical microtubule organization.