Lysyl hydroxylase

procollagen-lysine 1, 2-oxoglutarate 5-dioxygenase 1
Identifiers
Symbol	PLOD1
Alt. symbols	LLH, PLOD
Entrez	5351
HUGO	9081
OMIM	153454
RefSeq	NM_000302
UniProt	Q02809
Other data
EC number	1.14.11.4
Locus	Chr. 1 p36.3-36.2

procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2
Identifiers
Symbol	PLOD2
Entrez	5352
HUGO	9082
OMIM	601865
RefSeq	NM_000935
UniProt	O00469
Other data
Locus	Chr. 3 q24

Lysyl hydroxylases (or procollagen-lysine 5-dioxygenases) are 2-oxoglutarate (2OG)-dependent dioxygenase enzymes that catalyze the hydroxylation of lysine to hydroxylysine. Lysyl hydroxylases require iron and vitamin C as cofactors for their oxidation activity. It takes place (as a post-translational modification) following collagen synthesis in the cisternae (lumen) of the rough endoplasmic reticulum (ER). There are three lysyl hydroxylases (LH1-3) encoded in the human genome, namely: PLOD1, PLOD2 and PLOD3. From PLOD2 two splice variant can be expressed (LH2a and LH2b), where LH2b differs from LH2a by incorporating the small exon 13A. LH1 and LH3 hydroxylate lysyl residues in the collagen triple helix, whereas LH2b hydroxylates lysyl residues in the telopeptides of collagen. In addition to its hydroxylation activity, LH3 has glycosylation activity that produces either monosaccharide (Gal) or disaccharide (Glc-Gal) attached to collagen hydroxylysines.

Collagen lysyl hydroxylation is the first step in collagen pyridinoline cross-linking, that is necessary for the stabilization of collagen.

Pathology

Mutations in the PLOD2 gene have been linked to Bruck syndrome in humans.

A deficiency in its cofactor, vitamin C, is associated with scurvy.

External links

• Lysyl+Hydroxylase at the US National Library of Medicine Medical Subject Headings (MeSH)