Galanin 甘丙肽

2020/08/20 admin

甘丙肽(甘氨酸-丙氨酸,代表牛甘丙肽中的N-和C-末端氨基酸;也是GAL)是3kDa(预测的),甘丙肽家族的分泌成员。它在各种神经元细胞类型中与不同的神经肽共表达。甘丙肽通过结合三个GPCR之一来影响多个代谢过程。GalR1阻断胰岛素分泌,GalR2启动神经发生,GalR3影响成瘾行为。人类甘丙肽原体的大小为11-12 kDa(预测值),长度为104个氨基酸(aa)。蛋白水解加工产生30 aa成熟的甘丙肽(aa 33-62),加上一个磷酸化(Ser117),C端59 aa GMAP片段,该片段显然参与了有害刺激的加工。一旦被分泌,甘丙肽可以经历另外的蛋白水解降解。在AA 2-123上,人Galanin脯氨酸与小鼠Galanin脯氨酸具有72%的氨基酸同一性。

Galanin (Glycine-Alanine, representing the N-and C-terminal amino acids in bovine Galanin; also GAL) is a 3 kDa (predicted), secreted member of the Galanin family of peptides. It is co-expressed with differing neuropeptides in a variety of neuron cell types. Galanin affects multiple metabolic processes by binding to one of three GPCRs. GalR1 blocks insulin secretion, GalR2 initiates neurogenesis and GalR3 influences addictive behavior. The human Galanin proform is 11-12 kDa in size (predicted) and 104 amino acids (aa) in length. Proteolytic processing generates a 30 aa mature Galanin peptide (aa 33-62), plus a phosphorylated (Ser117), C-terminal 59 aa GMAP fragment that is apparently involved in the processing of noxious stimuli. Once secreted, Galanin can undergo additional proteolytic degradation. Over aa 2-123, the human Galanin proform shares 72% aa identity with mouse Galanin proform.

The galanin gene is located on human chromosome 11q13.3, rat chromosome 1q42, and mouse chromosome 19A. The peptide precursor of galanin is encoded by a single-copy gene consisting of six small exons spanning about 6 kb of genomic DNA. Regarding its structure, a sequence of galanin is followed by the signal peptide, and the remainder is called galanin message-associated peptide (GMAP) 

-Andrew L. Gundlach, Philip J. Ryan, in Handbook of Biologically Active Peptides (Second Edition), 2013

Galanin (GAL) is a 29–30 amino acid peptide that is well-conserved among species, including rats and humans. It is widely distributed throughout the brain, including the emotion-regulating amygdala and the feeding-regulating hypothalamus. Within the hypothalamus, GAL is expressed in many neuronal populations, including the paraventricular nucleus (PVN), dorsomedial nucleus, and arcuate nucleus. This peptide is involved in many physiological and psychological processes, including pain, epilepsy, and depression; however, it is also important in ingestive behavior, which is the focus of this review.

-Jessica R. Barson, ... Sarah F. Leibowitz, in Handbook of Biologically Active Peptides (Second Edition), 2013