Molecular cloning and expression of a new α‐subunit of soluble guanylyl cyclase Interchangeability of the α‐subunits of the enzyme

摘要

>A cDNA coding for a new subunit of soluble guanylyl cyclase with a calculated molecular mass of 81.7 kDa was cloned and sequenced. On the basis of sequence homology, the new subunit appears to be an isoform of the α₁‐subunit and was designated α₂ as the new subunit is very similar to the α₁‐subunit in the middle and C‐terminal part: it is quite diverse in the N‐terminal part. Preceding experiments had shown that coexpression of the α₁‐ and β₁‐subunits is necessary to obtain a catalytically active guanylyl cyclase in COS cells [(1990) FEBS Lett. 272, 221–223]. The finding that the α₂‐subunit was able to replace the α₁‐ but not the β₁‐subunit in expression experiments demonstrates the interchangeability of the α‐subunit isoforms of soluble guanylyl cyclase.