P3H1 gene
prolyl 3-hydroxylase 1
The P3H1 gene provides instructions for making an enzyme called prolyl-3 hydroxylase 1 (sometimes known as leprecan). This enzyme works with two other proteins, cartilage associated protein and cyclophilin B, as part of a complex that helps process certain forms of collagen. Collagens are proteins that provide strength, support, and the ability to stretch (elasticity) to many body tissues.
The complex modifies a protein building block (amino acid) called proline in collagen molecules. This modification, which is known as proline 3-hydroxylation, appears to be critical for the normal folding and assembly of collagen. It also may be important for releasing collagen molecules into the spaces around cells (the extracellular matrix). The secretion of collagen from cells is necessary for the proper formation of connective tissues, such as bones, tendons, and cartilage, that form the body's supportive framework.
Studies suggest that prolyl-3 hydroxylase 1 has several additional functions. For example, this enzyme may play a role in interactions between certain types of cells and the extracellular matrix that surrounds them. Other research indicates that prolyl-3 hydroxylase 1 may act as a tumor suppressor, preventing cells from growing and dividing too fast or in an uncontrolled way.
Related Information
At least four mutations in the P3H1 gene have been identified in people with a rare, severe form of osteogenesis imperfecta classified as type VIII. These mutations prevent cells from producing any functional prolyl-3 hydroxylase 1. Without this enzyme, certain forms of collagen are not modified through proline 3-hydroxylation. The altered collagen molecules are incorrectly folded, and some abnormal collagen is secreted from cells more slowly than usual. These collagen defects weaken connective tissues, resulting in extremely slow growth and thin, brittle bones that may fracture before birth.
Related Information
Cytogenetic Location: 1p34.2, which is the short (p) arm of chromosome 1 at position 34.2
Molecular Location: base pairs 42,746,335 to 42,767,084 on chromosome 1 (Homo sapiens Annotation Release 108, GRCh38.p7) (NCBI)
Related Information
- GROS1
- growth suppressor 1
- Leucine- and proline-enriched proteoglycan 1
- MGC117314
- P3H1_HUMAN
Related Information
- Molecular Biology of the Cell (fourth edition, 2002): Collagens Are the Major Proteins of the Extracellular Matrix
- Molecular Cell Biology (fourth edition, 2000): Collagen: The Fibrous Proteins of the Matrix
- National Institute of Child Health and Human Development: Second Gene Discovered for Recessive Form of Brittle Bone Disease (February 8, 2007)
- The Cell: A Molecular Approach (second edition, 2000): Collagen fibrils (figure)
- Cabral WA, Chang W, Barnes AM, Weis M, Scott MA, Leikin S, Makareeva E, Kuznetsova NV, Rosenbaum KN, Tifft CJ, Bulas DI, Kozma C, Smith PA, Eyre DR, Marini JC. Prolyl 3-hydroxylase 1 deficiency causes a recessive metabolic bone disorder resembling lethal/severe osteogenesis imperfecta. Nat Genet. 2007 Mar;39(3):359-65. Epub 2007 Feb 4. Erratum in: Nat Genet. 2008 Jul;40(7):927.
- Kaul SC, Sugihara T, Yoshida A, Nomura H, Wadhwa R. Gros1, a potential growth suppressor on chromosome 1: its identity to basement membrane-associated proteoglycan, leprecan. Oncogene. 2000 Jul 27;19(32):3576-83.
- Marini JC, Cabral WA, Barnes AM, Chang W. Components of the collagen prolyl 3-hydroxylation complex are crucial for normal bone development. Cell Cycle. 2007 Jul 15;6(14):1675-81. Epub 2007 May 18. Review.
- Vranka JA, Sakai LY, Bächinger HP. Prolyl 3-hydroxylase 1, enzyme characterization and identification of a novel family of enzymes. J Biol Chem. 2004 May 28;279(22):23615-21. Epub 2004 Mar 24.
- Wassenhove-McCarthy DJ, McCarthy KJ. Molecular characterization of a novel basement membrane-associated proteoglycan, leprecan. J Biol Chem. 1999 Aug 27;274(35):25004-17.