ANXA2 and Patent ductus arteriosus: To test whether phosphorylation of ANXA2 at Tyr23 isimportant for its localization to the PDA cell surface, we generated a panel ofplasmids expressing either wild-type ANXA2 (ANXA2WT), the ANXA2mutant protein (ANXA2Y23A) in which Tyr23 was altered to an alanineresidue making a non-phosphorylatable mutant, or the ANXA2 mutant protein(ANXA2Y23E) in which Tyr23 was altered to a glutamic acid residuemimicking constitutive phosphorylation.