Biology:Type I collagen

Short description: Type of connective tissue in animals

collagen, type I, alpha 1
Identifiers
Symbol	COL1A1
NCBI gene	1277
HGNC	2197
OMIM	120150
RefSeq	NM_000088
UniProt	P02452
Other data
Locus	Chr. 17 q21.3-q22

collagen, type I, alpha 2
Identifiers
Symbol	COL1A2
Alt. symbols	OI4
NCBI gene	1278
HGNC	2198
OMIM	120160
RefSeq	NM_000089
UniProt	P08123
Other data
Locus	Chr. 7 q21.3-22.1

Type I collagen is the most abundant collagen of the human body. It forms large, eosinophilic fibers known as collagen fibers. It is present in scar tissue, the end product when tissue heals by repair, as well as tendons, ligaments, the endomysium of myofibrils, the organic part of bone, the dermis, the dentin, and organ capsules.

Formation

The COL1A1 gene produces the pro-alpha1(I) chain. This chain combines with another pro-alpha1(I) chain and also with a pro-alpha2(I) chain (produced by the COL1A2 gene) to make a molecule of type I pro-collagen. These triple-stranded, rope-like pro-collagen molecules must be processed by enzymes outside the cell. Once these molecules are processed, they arrange themselves into long, thin fibrils that cross-link to one another in the spaces around cells. The cross-links result in the formation of very strong mature type I collagen fiber.

Clinical significance

See Collagen, type I, alpha 1

Markers used to measure bone loss are not easily testable. Degradation of type 1 collagen releases metabolites that can be used to monitor resorption.

See also

• Collagen
• Type II collagen
• Collagen, type I, alpha 1
• Collagen, type I, alpha 2
• Collagen, type III, alpha 1

Further reading

• Junqueira's basic histology: text and atlas.. McGraw-Hill Education. 2018. pp. 106. ISBN 978-1-260-02618-4. 

External links

• Collagen+type+I at the US National Library of Medicine Medical Subject Headings (MeSH)