Zusammenfassung der Ressource
Cell adhesion
- CELL ADHESION
and MIGRATION
- Failure to migrate and
aggregate leads to cell,
tissue and organism
dysfunction and death
- Many cells die anyway
- CLASSICAL STUDIES
- Classical cell aggregation (H.V. Wilson 1907)
- Sponges can re – aggregate, and by species
- Embryonic tissues re-sort by tissues
- In large re-aggregates see regionalisation
- L CELLS
- Express no cadherins
- Transfection induces homophilic sorting
- Transfection induces graded sorting
- Important general principles mboc 4th ed 19-27
- MONOCLONAL ANTIBODIES
- Monoclonal antibodies led to CAM identification
- MBC 4th Ed 8-6
- CELL ADHESION
MOLECULES -
REVISION
- Families
- Ca2+ dependent or Ca2+ - independent
- Ca2+ INDEPENDENT CAMS
- Numerous – major
forms are the neural
cell adhesion
molecules (N-CAMs)
- Homophilic binding
- ECM and cell binding
- Single gene,
alternative splicing
and post
translational
glycosylation
- variable polysialic acid
- more in immature
- more = less adhesion
- MBC 4th Ed 19-31
- Ca2+ dependent are
cadherins, selectins
(and integrins)
- CADHERINS
- Integral membrane
glycoproteins 720-750
amino acids
- Ca2+ - conformation
change and binding
- MBC 5th Ed 19-9b
- MBC 5th Ed 19-7
and Table 19-3
- And hypervariable protocadherins
- e.g. at synapses
- role in specifying synapses?
- MBC 4th Ed 19-28
- CADHERINS IN THE EARLY NERVOUS SYSTEM
- Only E-cadherin expressed in early embryo
- Newly formed mesoderm cells lose E-cadherin
- N-cadherin replaces E-cadherin in neural tube
- Complex changes in neural crest cells during migration
- MBC 4th Ed 19-25, 5th Ed 19-12c
- CATENINS
- Catenins link to actin
- β catenin can regulate proliferation via c - myc
- MBC 4th Ed 15-72 and
19-29, 5th Ed 19-14
- SELECTINS
- Cell surface, Ca2+ dependent ,
carbohydrate binding
- e.g. neutrophil trapping
- MBC 4th Ed 19-30