Isolation and primary structure of pituitary human galanin, a 30-residue nonamidated neuropeptide.

The early diagnosis of colorectal cancer and the early detection of recurrence are central to effective treatment, as prognosis is directly related to the stage of the disease. When colorectal cancer is diagnosed at an early, localized stage, 5-year survival is 90%. There is substantial interest in the identification of circulating human tumor-derived proteins in serum for the purposes of early cancer diagnosis. We have implemented an approach based on the analysis of microarray data for the identification of tumor proteins that may have utility as biomarkers in colon cancer. Expression analysis of microarray data obtained from a variety of 290 tumors and normal tissues revealed that galanin was maximally expressed in colon cancer. These findings were corroborated by real-time quantitative PCR, in which the colon cancer cell lines LOVO, HCT15, SW480, and SW620 cell showed significantly higher levels of galanin expression than did noncolon cancer cell lines. To evaluate galanin as a potential biomarker of colon cancer, a preliminary ''training'' set of serum from 40 healthy donors and 55 colon cancer patients was analyzed by ELISA. The data pattern was confirmed by an independent set of 90 masked serum samples: 24 from healthy donors and 66 from colon cancer patients. This result yielded a sensitivity of 69.7% [95% confidence interval (95% CI), 57.1-80.4], specificity of 75.0% (95% CI, 53.3-90.2), and positive predictive value of 88.5% (95% CI, 76.6-95.7). The galanin expression level was significantly increased with tumor size and tumor stage. These findings justify a prospective assessment of serum galanin protein as a screening tool for colon cancer. (Cancer Epidemiol Biomarkers Prev 2007;16(11):2373 -8)

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“…The first 14 amino acids are fully conserved in almost all species (5). Galanin is found in the brain and the gut.…”

Section: Introductionmentioning

confidence: 99%

Galanin Is Up-Regulated in Colon Adenocarcinoma

Kim¹,

Kee²,

Chong

et al. 2007

Cancer Epidemiology, Biomarkers &Amp; Prevention

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“…PACAP analogues were synthesized on an automatic solid-phase peptide synthesizer as described [22,23]. HPLCpurified peptides were characterized by time-of-flight mass spectrometry (Bio Ion 20, Applied Biosystems).…”

Section: N-9-fluorenylmethoxycarbonyl-peptide Synthesismentioning

confidence: 99%

Characterization and purification of the solubilized pituitary adenylate‐cyclase‐activating polypeptide‐1 receptor from porcine brain using a biotinylated ligand

Schäfer

Schmidt

1993

European Journal of Biochemistry

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A specific receptor for the brain-gut neuropeptide pituitary adenylate-cyclase-activating polypeptide (PACAP-1 receptor) was solubilized with Chapso from porcine brain plasma membranes and purified. Binding of '251-PACAP(1 -27) to the solubilized material was reversed equipotently by unlabeled PACAP(1-27) and PACAP(1-38). Soluble receptors retained the binding affinities and specificities of the plasma membrane fraction. Scatchard analysis of equilibrium-binding data indicated the existence of a single high-affinity binding site (Kd = 0.23 nM, Bmax = 1.2 pmol/mg protein). Binding of 1251-PACAP(1 -27) to solubilized receptors was not affected by guanosine nucleotides, suggesting that solubilization dissociates the PACAP-1 receptor/guanosine-nucleotidebinding protein complex. Affinity cross-linking of lZ51-PACAP(1 -27) to soluble PACAP-1 receptors identified a specifically labeled 60-kDa protein. Enzymic deglycosylation of soluble affinitylabeled receptors reduced the apparent molecular mass by 10 kDa. The solubilized receptor glycoprotein was purified 4-5-fold by lectin-adsorption chromatography on wheatgerm agglutinin immobilized on agarose. S-Biotinyl[Ala28 -34, Cys35]PACAP(1-35) was synthesized, immobilized on streptavidin-coated magnetic Sepharose beads and used to further affinity-purify wheatgerm-agglutinin-eluted receptor material. This more than 6000-fold enriched PACAP-1-receptor-preparation retained single-class high-affinity binding and consisted of an almost homogenous 55 -60-kDa protein identified by silver staining. In conclusion, we established a rapid method for purification of PACAP-1 receptors, allowing further studies to be performed by protein chemistry.PACAP represents a novel neuropeptide that exists as two C-terminally amidated molecular forms; PACAP(1-38) and PACAP vasoactive intestinal peptide (VIP). Therefore, PACAP is regarded as a member of the secretinlglucagonNIP family of structurally related regulatory peptides. Yet, several biological effects of PACAP on pituitary [5-71, pancreatic [8, 91 and intestinal function [lo-131 have been described, qualifying PACAP as a brain-gut peptide. PACAP is widely expressed in gastrointestinal and nervous tissues [14-161 and binds specifically to at least two receptor types; PACAP-1 receptors present in brain [17, 181 and gastrointestinal muscles [ 11 -131 and PACAP-2NIP receptors, similar or identical to the previously described VIP receptor. PACAP-1 receptors have been identified in various mammalian tissues as a 60-kDa protein [19-221, linked to a GTP-binding protein. To gain insight into the mechanisms by which PACAP exerts its action as neuromodulatory peptide, biochemical and molecular characterization of the PACAP-1 receptor is highly desirable. Therefore, we investigated the binding properties of the solubilized PACAP-1 receptor from porcine brain and developed a simple straight-forward strategy for receptor purification based on lectin-adsorption chromatography on immobilized wheatgerm agglutinin and ligand-affinity chromatography usi...

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“…Human galanin (GAL) is a 30 amino-acid neuropeptide, proteolytically processed from preprogalanin (PPGAL) (Evans and Shine, 1991;Schmidt et al, 1991). PPGAL is a single-copy gene located on chromosome 11q13.3-13.5, spanning over 6 kb of genomic DNA and organized into six exons (Rokaeus and Brownstein, 1986;Vrontakis et al, 1987).…”

Section: Introductionmentioning

confidence: 99%

Gender-Specific Association of Galanin Polymorphisms with HPA-Axis Dysregulation, Symptom Severity, and Antidepressant Treatment Response

Unschuld

Ising

Roeske

et al. 2010

Neuropsychopharmacol

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Galanin (GAL) is an estrogen-inducible neuropeptide, highly expressed in brain regions reported to be involved in regulation of mood and anxiety. GAL possibly has a direct modulatory effect on hypothalamic-pituitary-adrenal (HPA)-axis regulation. Recent data from pharmacological and genetic studies indicate a significant function of GAL in stress-related disorders. By using a tag SNP approach covering the locus encoding preprogalanin (PPGAL), earlier findings of female-specific associations of polymorphisms in this locus with panic disorder were expanded to a larger sample of 268 outpatients with anxiety disorders (ADs). Within a larger sample of 541 inpatients with major depressive disorder (MDD), we then tested associations of one PPGAL tag SNP with specific depression symptom clusters and HPA-axis activity assessed by the combined dexamethasone-suppression/CRH-stimulation test both at inpatient admission and discharge (n ¼ 298). Gender specificity as well as dependence of the association on levels of circulating estrogens was analyzed. Genotyping revealed high linkage disequilibrium in the promoter area of the PPGAL gene, which includes several estrogen-response elements. Confirming earlier results, rs948854, tagging this promoter region, was associated with more severe anxiety pathology in female AD patients, but not in males. In premenopausal female MDD patients, the same allele of rs948854 was associated with more severe vegetative but not cognitive depressive symptoms at discharge and worse treatment response on antidepressant medication. Furthermore, this allele was associated with higher HPA-axis activity at admission. No significant case-control associations could be observed. However, because of power limitations of both patient samples, small effects cannot be excluded. The reported associations in independent samples of AD and MDD support an estrogen-dependent function of GAL in pathophysiology of anxiety and depression, affecting response to antidepressant treatment.

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Isolation and primary structure of pituitary human galanin, a 30-residue nonamidated neuropeptide.

Cited by 66 publications

References 41 publications

Galanin Is Up-Regulated in Colon Adenocarcinoma

Galanin Is Up-Regulated in Colon Adenocarcinoma

Characterization and purification of the solubilized pituitary adenylate‐cyclase‐activating polypeptide‐1 receptor from porcine brain using a biotinylated ligand

Gender-Specific Association of Galanin Polymorphisms with HPA-Axis Dysregulation, Symptom Severity, and Antidepressant Treatment Response

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