Thursday, August 28, 2014




Cadherin

: Calcium (Ca2+) -dependent adhesion, class of type -1 transmembrane proteins.

Important roles: cell adhesion, forming adherens junctions to bind cells within tissues together.

The cadherin superfamily:  cadherins, protocadherins, and atypical cadherins (Fat, Dachsous, and Flamingo)

 Each cadherin has a small cytoplasmic component, a transmembrane component, and the remaining bulk of the protein is extra-cellular (outside the cell).

Tissue morphogenesis during development is dependent on activities of the cadherin family of cell–cell adhesion proteins.

The extracellular domain of cadherins contains characteristic repeats that regulate homophilic and heterophilic interactions during adhesion and cell sorting.

Although cadherins may have originated to facilitate mechanical cell–cell adhesion, they have evolved to function in many other aspects of morphogenesis. Cadherin also interactions with a wide range of binding partners that modify their expression and adhesion activity by local regulation of the actin cytoskeleton and diverse signaling pathways.



http://www.fastbleep.com/biology-notes/31/178/1022
Halbleib J. Cadherins in development: cell adhesion, sorting, and tissue morphogenesis.Genes & Dev. 20: 3199-3214.      



Fibroblast growth factor (FGFs)

: A family of growth factor.

Involved in: angiogenesis, wound healing, embryonic development and various endocrine signaling pathways

The FGFs: heparin-binding proteins and interactions with cell-surface-associated heparin sulfate proteoglycans: be essential for FGF signal transduction.

Important role:  involved in the regulation of many developmental processes including patterning, morphogenesis, differentiation, cell proliferation or migration.

The FGFs: are secreted molecules which function through the activation of specific tyrosine kinases receptors, the FGF receptors that transduce the signal by activating different pathways including the Ras/MAP kinase and the phospholipase-C gamma pathways.

 FGFs are such a diverse set of activities requires a tight control of the transduction signal which is achieved through the induction of different feedback inhibitors such as the Sproutys, Sef and MAP kinase phosphatase 3 which are responsible for the attenuation of FGF signals, limiting FGF activities in time and space.
                             


http://www.nature.com/nrn/journal/v8/n8/full/nrn2189.html
Thisse B,Thisse Ch.Functions and regulations of fibroblast growth factor signaling during embryonic development   .Developmental Biology, Volume 295, Issue 1, 1 July 2006, Page 294.



Wnt signaling pathway

: are a group of signal transduction pathways made of proteins that pass signals from outside of a cell through cell surface receptors to the inside of the cell.

Three Wnt signaling pathways: the canonical Wnt pathway, the noncanonical planar cell polarity pathway, and the noncanonical Wnt/calcium pathway.

The embryonic processes include:  body axis patterning, cell fate specification, cell proliferation, and cell migration.  These processes are necessary for proper formation of important tissues including bone, heart, and muscle.

 Its role in embryonic development was discovered when genetic mutations in proteins in the Wnt pathway produced abnormal fruit fly embryos. Later research found that the genes responsible for these abnormalities also influenced breast cancer development in mice.
http://molehr.oxfordjournals.org/content/15/4/215/F1.expansion.
Tata Purushothama Rao,Michael KühlAn. Updated Overview on Wnt Signaling Pathways.
 .Circulation Research. 2010;106:12 1798-1806.