Zmudzinski, "Mass spectrometry identification of granins
and other proteins secreted by neuroblastoma cells," Tumor Biology, vol.
Granins are precursor proteins that can give rise to a large number of small bioactive peptides, involved in different biological functions (Table 1).
Chromogranin A is a 439-residue-long glycoprotein [15,16], a member of a larger family of soluble secretory proteins (granin proteins) that includes also chromogranin B (CgB), secretogranin (Sg) II (CgC), Sg III (1B1075), Sg IV (HISL-19), Sg V (7B2) and Sg VI (NESP55), Sg VII (VGF), and Sg VIII (proSAAS) , localized in secretory granules of neuroendocrine cells, neurons, and the adrenal medulla .
Instead, BRCA1 is a secreted molecule belonging to an obscure family of proteins known as granins, the investigators said (SN: 3/2/96, p.
In addition, according to other researchers at a recent meeting on BRCA1, the Seattle-Nashville collaboration reiterated its belief that the gene's protein is a secreted granin. (Members of the collaboration did not return calls from Science News.)
Adding to that hope is a more controversial result from the same researchers: They contend that BRCA1, the protein encoded by BRCA1, is secreted by breast cells and belongs to an obscure family of proteins called granins. If these observations are correct, BRCA1's role may differ from that of other known tumor-suppressing genes, most of whose proteins act within the cell to control proliferation.
Researchers then noted that BRCA1 contains an unusual string of 10 amino acids, known as the granin motif.
Chromogranins, including chromogranin A (CgA), are members of the granin
family of neuroendocrine secretory proteins located in the secretory vesicles of neurons and endocrine cells.
Secretoneurin (SN) is a 33-amino acid peptide belonging to the chromogranin-secretogranin (granin) protein family (2).
The extended granin family: structure, function, and biomedical implications.
The human chromogranin A (CgA) protein, a member of the granin
family, is an acidic 439 amino acid protein with a sequence containing several mono--and dibasic cleavage sites.
Human chromogranin A (CgA), a member of the granin
family, is an acidic 439-amino acid protein with a widespread expression in endocrine cells and neurons (1-3).