Linked Life Data

16601136

Source:http://linkedlifedata.com/resource/pubmed/id/16601136

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2006-6-16
pubmed:abstractText
Annexin 1 (ANXA1), a 37-kDa protein, is a member of the superfamily of Ca(2+)- and phospholipid-binding annexin proteins. In the anterior pituitary, ANXA1 is expressed mainly by folliculostellate (FS) cells and mediates the early delayed feedback inhibition exerted by glucocorticoids on the release of ACTH and other pituitary hormones. It has been previously demonstrated that TtT/GF cells (a FS cell line) express and externalize ANXA1 in response to glucocorticoid treatment. However, ANXA1 lacks a cleavable signal sequence and externalization is not affected by inhibitors of the secretory pathway. We have previously shown that glyburide, an ATP-binding cassette (ABC) transporter inhibitor, inhibits the externalization of ANXA1 from TtT/GF cells and pituitary tissue. Here we investigated whether ABCA1 is involved in ANXA1 externalization. The use of the ABCA1-transporter inhibitors geranyl-geranyl pyrophosphate and sulfobromophthalein significantly inhibited ANXA1 externalization. Partial silencing of ABCA1 expression in TtT/GF cells by siRNA also significantly decreased the amount of cell surface ANXA1. However, anterior pituitary tissue from ABCA1-null mice was found to externalize ANXA1 normally. Because compensation by other ABC family members may occur in vivo, ANXA1 externalization was studied in two transfection models: Xenopus oocytes injected with ABCA1 mRNA and AtT20 D1 corticoctroph cells cotransfected with ABCA1-green fluorescent protein and ANXA1. ABCA1-expressing oocytes, but not water-injected controls, were found to externalize ANXA1. Expression of ABCA1 in AtT20 D1 cells significantly increased the amount of cell surface ANXA1, compared with mock-transfected and ANXA1-only transfected controls. Together these data provide evidence for a role of ABCA1 in ANXA1 export.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
147
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3219-27
pubmed:dateRevised
2007-8-13
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Evidence for the role of adenosine 5'-triphosphate-binding cassette (ABC)-A1 in the externalization of annexin 1 from pituitary folliculostellate cells and ABCA1-transfected cell models.
pubmed:affiliation
Department of Physiology, Anatomy, and Genetics, Le Gros Clark Building, University of Oxford, South Parks Road, Oxford OX1 3QX, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't