The primary structure of human secretogranin I (chromogranin B): comparison with chromogranin A reveals homologous terminal domains and a large intervening variable region.

Abstract

Communicated by B.DobbersteinWe have determined and analyzed the primary structure of human secretogranin I (chromogranin B), a tyrosine-sulfated secretory protein found in a wide variety of peptidergic endocrine cells. A 2.5-kb cDNA clone, hybridizing to an mRNA of similar length, was isolated from a cDNA library of human pheochromocytoma. The identity of the clone was established by comparison of its deduced amino acid sequence with N-terminal and several internal secretogranin I sequences as well as by immunoprecipitation of the protein produced by in vitro transcription-translation of the cloned cDNA.Secretogranin I is a 657 amino acid long polypeptide of 76 kd and is preceded by a cleaved N-terminal signal peptide of 20 residues. Comparison of the predicted amino acid sequence of human secretogranin I with that of bovine chromogranin A reveals significant homologies near the N termini and at the C termini. The N-terminal homologous domains contain the only two cysteine residues of both proteins and form disulfide-stabilized loop structures. The sequences between the homologous terminal domains in both proteins differ but are characterized by a remarkable hydrophilicity, an abundance of acidic amino acids and potential dibasic cleavage sites for the generation of smaller, perhaps hormone-like, peptides.

An integrated genomic analysis of gene-function correlation on schizophrenia susceptibility genes

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“…Since there are only two cysteine residues in the entire CGA molecule and these two cysteines are located in the 17th and 38th positions from the N-terminus [17,18], formation of the compact N-terminal core structure may owe its existence to a disulfide bond formed between the two cysteines [19]. In our previous studies, it was shown that chromogranin A bound more Ca" at pH 5.5 than at pH 7.5, i.e.…”

Ubiquitous presence of chromogranin A in the inner ear of guinea pig

“…In addition, the same antibody also reacted with a protein of -110 kDa in several of these tissues. However, the identity of the band is not clear at present although chromogranin B [15], another member of the chromogranin family, has a size of -110 kDa on the SDS-gel and has previously been shown to crossreact with a chromogranin A antibody [ 161. In parallel experiments, an identical protein blot was also immunoreacted with the monoclonal antibody.…”