Integrin beta-8 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the ''ITGB8''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Function
This gene is a member of the
integrin
Integrins are transmembrane receptors that help cell–cell and cell–extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle, o ...
beta chain family and encodes a single-pass type I membrane protein with a VWFA domain and four cysteine-rich repeats. This protein noncovalently binds to an alpha subunit to form a
heterodimeric
In biochemistry, a protein dimer is a macromolecular complex or multimer formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ...
integrin complex. In general, integrin complexes mediate cell-cell and cell-
extracellular matrix
In biology, the extracellular matrix (ECM), also called intercellular matrix (ICM), is a network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide structural and bio ...
interactions and this complex plays a role in human airway epithelial proliferation. Alternatively spliced variants which encode different protein isoforms have been described; however, not all the variants have been fully characterized.
Additionally, it has been shown to interact with RhoGDI1 to alter the activation of Rho GTPases to promote Glioblastoma cell invasiveness. Uncoupling the αvβ8-RhoGDI1 interaction has been seen to block GBM cell invasion by hyperactivating Rho GTPases.
Clinical significance
High expression levels of ITGB8 are associated with high
angiogenic
Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature mainly by processes of sprouting and s ...
and poorly
invasive glioblastoma
Glioblastoma, previously known as glioblastoma multiforme (GBM), is the most aggressive and most common type of cancer that originates in the brain, and has a very poor prognosis for survival. Initial signs and symptoms of glioblastoma are nons ...
tumors. Conversely low expression of ITGB8 correlates with highly invasive but low angiogenic tumors.
References
Further reading
*
*
*
*
*
*
*
*
*
*
*
*
*
External links
ITGB8Info with links in th
Cell Migration Gateway
Integrins
{{gene-7-stub