Updated project metadata. Soluble guanylyl cyclase (GC1) is an α/β heterodimer producing cGMP when stimulated by nitric oxide (NO). The NO-GC1-cGMP pathway is essential to cardiovascular homeostasis but is disrupted by oxidative stress, which induces GC1 desensitization to NO by S-nitrosation (SNO) of its cysteines (C). We discovered that under these conditions, GC1-α subunit increases cellular S-nitrosation via transfer of its nitrosothiols to other proteins (transnitrosation). One of the SNO-targets was the oxidized form of the oxido-reductase Thioredoxin1 (oTrx1), which is unilaterally transnitrosated by GC1. GC1-αC610 was a major SNO-donor to oTrx1-C73. Because oTrx1 itself drives transnitrosation, we sought and identified several SNO-proteins targeted by both GC1 and oTrx1. Among them, transnitrosation of RhoA by SNO-GC1 requires oTrx1 as a nitrosothiol relay, suggesting a SNO-GC1→oTrx1→RhoA cascade. We showed that RhoA pathway, which is antagonized by the canonical NO-cGMP signaling, was alternatively inhibited by GC1-α-dependent S-nitrosation under oxidative conditions. We propose that some SNO-GC1’ functions are adaptive responses triggered by oxidation of the canonical NO-cGMP pathway