• Secretogranin III, also known as SCG3, is a member of the chromogranin-secretogranin family of neuroendocrine secretory proteins, collectively referred to as granins. Additional members of this family include secretogranin II, IV, and V, chromogranin A and B, and a few additional related proteins. SCG3 is synthesized as an N-glycosylated protein and two isoforms can be generated from alternative splicing.
• SCG3 has been implicated in diabetic retinopathy (DR) and retinopathy of prematurity (ROP) as a disease-associated endothelial ligand, thus suggesting SCG3 is a promising target for novel antiangiogenic therapy of DR and ROP.

Western blot analysis of SCG3 protein expression in homozygous B-hSCG3 mice. Various tissue lysates were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hSCG3 mice (H/H), and then analyzed by western blot with anti-SCG3 antibody(Santa Cruz, sc-271750). 40 μg total proteins were loaded for western blotting analysis. Human and mouse SCG3 protein were detectable in homozygous B-hSCG3 mice and wild-type mice.

Strain specific analysis of SCG3 mRNA expression in wild-type C57BL/6 mice and B-hSCG3 mice by RT-PCR. Brain RNA were isolated from wild-type C57BL/6 mice (+/+) and homozygous B-hSCG3 mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human SCG3 primers. Mouse Scg3 mRNA were detectable only in wild-type C57BL/6 mice. Human SCG3 mRNA was detectable only in homozygous B-hSCG3 mice but not in wild-type mice.