The IND domain of PIAL2 is responsible for MOM1-PIAL2 interaction and PIAL2 dimerization <i>in vivo</i>.

<p><b>(A)</b> Schematic diagram of mutations in the IND domain of PIAL2. Black squares represent the conserved amino acids. PIAL2-IND-M represents the mutations in the IND domain (D182A/F183A/I185A, shown in red). <b>(B)</b> The interaction between MOM1 and PIAL2 or PIAL2-IND-M as determined by yeast two-hybrid assays. MOM1 was fused to GAL4-BD in the <i>pGBKT7</i> vector; PIAL2 and PIAL2-IND-M were fused to GAL4-AD in the <i>pGADT7</i> vector. “Vec” represents the empty <i>GAL-BD</i> or <i>GAL4-AD</i> vectors. <b>(C)</b> The IND mutations impair the interaction between PIAL2 and MOM1 as determined by affinity purification followed by mass spectrometric analysis. Protein extraction from transgenic plants separately harboring the wild-type <i>PIAL2</i> and <i>PIAL2-IND-M</i> transgene were subjected to affinity purification. <b>(D)</b> The interaction of MOM1-Flag with the wild-type PIAL2-Myc and the PIAL2-IND-M-Myc as determined by co-IP. <b>(E)</b> The interaction of Flag-PIAL2 with the wild-type PIAL2-Myc and the PIAL2-IND-M-Myc as determined by co-IP.