Identification and localization of 7B2 protein in human, porcine, and rat thyroid gland and in human medullary carcinoma.
The novel, highly conserved polypeptide 7B2, which belongs to a new protein superfamily, was isolated from human and porcine hypophysis. The availability of a specific antibody to a synthetic fragment enabled 7B2 localization in a number of neurocrine and endocrine tissues and revealed its secretory character. 7B2 was purified from thyroid homogenates by HPLC chromatography and characterized by gel permeation chromatography (dimeric mol wt, approximately 40,000) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (monomeric mol wt, 20,750). By immunocytochemistry 7B2 was colocalized with calcitonin in parafollicular cells and identified within secretory granules by electron microscopy. Three of nineteen human medullary carcinoma cases showed immunoreactive 7B2 within the early and late hyperplasia stages and neoplasia. Results suggest that 7B2 may play a role in endocrine function, possibly as a secretory substance, and may be a histochemical marker in addition to calcitonin for medullary carcinoma.
Marcinkiewicz
M
M
J. A. de Sève Laboratories of Biochemical and Molecular Neuroendocrinology, Clinical Research Institute of Montreal, Quebec, Canada.
Benjannet
S
S
Falgueyret
J P
JP
Seidah
N G
NG
Schürch
W
W
Verdy
M
M
Cantin
M
M
Chrétien
M
M
D000818:Animals; D002116:Calcitonin / Q000032:analysis; D002277:Carcinoma / Q000032:analysis*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003594:Cytoplasmic Granules / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007124:Immunoenzyme Techniques; D008854:Microscopy, Electron; D008970:Molecular Weight; D009419:Nerve Tissue Proteins; D051859:Neuroendocrine Secretory Protein 7B2; D010907:Pituitary Hormones / Q000032:analysis*; D051381:Rats; D013552:Swine; D013961:Thyroid Gland / Q000032:analysis*; D013964:Thyroid Neoplasms / Q000032:analysis*
D009419:Nerve Tissue Proteins; D051859:Neuroendocrine Secretory Protein 7B2; D010907:Pituitary Hormones; C497678:SCG5 protein, human; C497680:Scg5 protein, rat; D002116:Calcitonin