Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2007-8-16
pubmed:abstractText
Septin filaments form ordered hourglass and ring-shaped structures in close apposition to the yeast bud-neck membrane. The septin hourglass scaffolds the asymmetric localization of many essential cell division proteins. However, it is unknown whether the septin structures have an overall polarity along the mother-daughter axis that determines the asymmetric protein localization. Here we engineered rigid septin- green fluorescent protein (GFP) fusions with various fluorescence dipole directions by changing the position of the GFP beta-barrel relative to the septin filament axis. We then used polarized fluorescence microscopy to detect potential asymmetries in the filament organization. We found that both the hourglass and ring filament assemblies have sub-resolution C(2) symmetry and lack net polarity along the mother-daughter axis. The hourglass filaments have an additional degree of symmetry relative to the ring filaments, most likely due to a twist in their higher-order structure. We previously reported that during the hourglass to rings transition septin filaments change their direction. Here we show that the filaments also undergo a change in their lateral organization, consistent with filament untwisting. The lack of net septin polarity along the mother-daughter axis suggests that there are no septin-based structural reasons for the observed asymmetry of other proteins. We discuss possible anisotropic processes that could break the septin symmetry and establish the essential bud-neck asymmetry.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
372
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
37-49
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Symmetry of septin hourglass and ring structures.
pubmed:affiliation
Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA. alinavrabioiu@gmail.com
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't