L10 Flashcards
what is the ECM
is a network of fibrous proteins and hydrated proteoglycans which surround cells in tissues
what are the functions of the ECM
provides strength and support
guides cell migration and polarity
permits intercellular communication
what does Maintenance of a healthy ECM depend on
balance between synthesis and breakdown of matrix molecules
How is a healthy ECM maintained
cells within ECM secrete the components of the ECM
the same cells also secrete enzymes which digest/breakdown these components
to remove damaged matrix
i.e. ‘remodel” matrix
what happens when matrix synthesis is higher than its breakdown
tissue scarring, fibrosis, cancer
(alteration of function)
what happens when matrix breakdown is higher than its synthesis
developmental/induced deficiencies/breakdown, Arthritis/metastasis
(loss of function)
what are proteinases
enzymes that break down proteins
what proteinases are intracellular
aspartic proteinases
cysteine proteinases
threonine proteinases
what proteinases are extracellular
serine proteinases
metallo-proteinases
what is the degradome
570 genes in in the human genome that encode proteinases
what are the domains of metalloproteinase
pre
pro
catalytic domain (CD)
substrate specific domain
which domain binds Zn 2+
CD
what domains are removed during secretion
Pre and Pre
what are the types of metalloproteinase
- MMP (matrix metalloproteinases)
- ADAM (a disintegrin-like and metalloproteinase)
- ADAMTS (a ADAM with thrombospondin motifs)
what additional domain do ADAMs have that MMPs don’t
disintegrin-like domain
give examples of MMPs
collagenases (MMP-1, -8, 13, 18)
gelatinases (MMP-2, -9)
stromelysins (MMP-3 -10, -11
matrilsins (MMP-7, -26)
membrane-type ((MT); MMP-14,-15, -16, -17 -23, -24, -25)