Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1998-1-9
pubmed:abstractText
The tumor suppressor maspin (mammary serpin) was originally identified as a component of human mammary epithelial cells that is downregulated as mammary tumor cells progress from the benign to the invasive and metastatic states. Maspin inhibits cellular invasion, motility, and proliferation, but its mechanism of action is currently unknown. Because the cellular machinery responsible for these processes is cytoplasmic, we have reexamined the tissue distribution and subcellular localization of maspin. We find that maspin, or a maspin-like protein, is present in many human organs, in which it localizes to epithelia. In cultured human mammary myoepithelial cells, maspin is predominantly a soluble cytoplasmic protein that associates with secretory vesicles and is present at the cell surface. In vitro assays show that the vesicle association is due to the existence of an uncleaved facultative secretion signal that allows small amounts of maspin to partition into the endoplasmic reticulum. These results demonstrate that maspin is more widespread than previously believed. The subcellular localization studies indicate that soluble intracellular and vesicle-associated maspin probably play an important role in controlling the invasion, motility, and proliferation of cells expressing it, whereas extracellular maspin may also regulate these processes in adjacent cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-1554
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1697-706
pubmed:dateRevised
2007-7-10
pubmed:meshHeading
pubmed-meshheading:9389773-Blotting, Northern, pubmed-meshheading:9389773-Breast, pubmed-meshheading:9389773-Cells, Cultured, pubmed-meshheading:9389773-Cytoplasm, pubmed-meshheading:9389773-Cytoplasmic Granules, pubmed-meshheading:9389773-DNA Primers, pubmed-meshheading:9389773-Epithelium, pubmed-meshheading:9389773-Female, pubmed-meshheading:9389773-Genes, Tumor Suppressor, pubmed-meshheading:9389773-Humans, pubmed-meshheading:9389773-Immunohistochemistry, pubmed-meshheading:9389773-Intestines, pubmed-meshheading:9389773-Male, pubmed-meshheading:9389773-Membrane Proteins, pubmed-meshheading:9389773-Proteins, pubmed-meshheading:9389773-RNA, Messenger, pubmed-meshheading:9389773-Serpins, pubmed-meshheading:9389773-Subcellular Fractions, pubmed-meshheading:9389773-Tissue Distribution, pubmed-meshheading:9389773-Tumor Cells, Cultured
pubmed:year
1997
pubmed:articleTitle
Maspin is an intracellular serpin that partitions into secretory vesicles and is present at the cell surface.
pubmed:affiliation
LXR Biotechnology, Inc., Richmond, California 94804, USA.
pubmed:publicationType
Journal Article