Structural and functional characterization of a second subfamily member of the calcium-modulated bovine rod outer segment membrane guanylate cyclase, ROS-GC2.
A native bovine calcium-modulated rod outer segment membrane guanylate cyclase (ROS-GC) has been cloned and reconstituted to show its linkage consistent to the process of phototransduction. In the present study, a second form of the membrane guanylate cyclase has been cloned from the bovine retina. This cyclase shares a high sequence identity with ROS-GC, is specifically expressed in the bovine retina, and, like ROS-GC, is modulated in low Ca2+ by a calmodulin-like Ca2+-binding protein, termed GCAP2. For this reason, this cyclase has now been named ROS-GC2 and the previously described ROS-GC as ROS-GC1. The tail end of ROS-GC2 contains a stretch of five amino acids, a structural feature unique to itself. These findings support the existence of a calcium-modulated subfamily of ROS-GC and indicate that ROS-GC2 embodies a five amino acid signature element at its tail end.
Goraczniak
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Department of Cell Biology, University of Medicine and Dentistry of New Jersey, Stratford 08084, USA.
Duda
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Sharma
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D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D018076:DNA, Complementary; D006162:Guanylate Cyclase / Q000737:chemistry* / Q000378:metabolism*; D008969:Molecular Sequence Data; D012374:Rod Cell Outer Segment / Q000737:chemistry* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship
D018076:DNA, Complementary; D006162:Guanylate Cyclase; D002118:Calcium