LECT1 explained

Chondromodulin-1 is a protein that in humans is encoded by the LECT1 gene.^{[1] [2] [3]}

Function

This gene encodes a glycosylated transmembrane protein that is cleaved to form a mature, secreted protein. The N-terminus of the precursor protein shares characteristics with other surfactant proteins and is sometimes called chondrosurfactant protein, although no biological activity has yet been defined for it. The C-terminus of the precursor protein contains a 25 kDa mature protein called leukocyte cell-derived chemotaxin-1 or chondromodulin-1. The mature protein promotes chondrocyte growth and inhibits angiogenesis. This gene is expressed in the avascular zone of prehypertrophic cartilage, and its expression decreases during chondrocyte hypertrophy and vascular invasion. The mature protein likely plays a role in endochondral bone development by permitting cartilaginous anlagen to be vascularized and replaced by bone. It may also be involved in the broad control of tissue vascularization during development. Alternative splicing results in multiple transcript variants encoding different isoforms.^[3]

Chondromodulin-I, an antiangiogenic factor isolated from cartilage, is abundantly expressed in cardiac valves. Gene targeting of chondromodulin-I resulted in enhanced VEGF-A expression, angiogenesis, lipid deposition and calcification in the cardiac valves of aged mice.^[4]

Further reading

• Hiraki Y, Shukunami C . Chondromodulin-I as a novel cartilage-specific growth-modulating factor . Pediatric Nephrology . 14 . 7 . 602–5 . July 2000 . 10912526 . 10.1007/s004670000339 . 20707816 .
• Hayami T, Shukunami C, Mitsui K, Endo N, Tokunaga K, Kondo J, Takahashi HE, Hiraki Y . Specific loss of chondromodulin-I gene expression in chondrosarcoma and the suppression of tumor angiogenesis and growth by its recombinant protein in vivo . FEBS Letters . 458 . 3 . 436–40 . September 1999 . 10570955 . 10.1016/S0014-5793(99)01201-6 . 31317770 .
• Yanagihara I, Yamagata M, Sakai N, Shukunami C, Kurahashi H, Yamazaki M, Michigami T, Hiraki Y, Ozono K . Genomic organization of the human chondromodulin-1 gene containing a promoter region that confers the expression of reporter gene in chondrogenic ATDC5 cells . Journal of Bone and Mineral Research . 15 . 3 . 421–9 . March 2000 . 10750556 . 10.1359/jbmr.2000.15.3.421 . free .
• Azizan A, Holaday N, Neame PJ . Post-translational processing of bovine chondromodulin-I . The Journal of Biological Chemistry . 276 . 26 . 23632–8 . June 2001 . 11323410 . 10.1074/jbc.M009967200 . free .
• Aoyama T, Okamoto T, Nagayama S, Nishijo K, Ishibe T, Yasura K, Tsuboyama T, Nakayama T, Nakashima Y, Nakamura T, Toguchida J . Expression of the chondromodulin-I gene in chondrosarcomas . Cancer Letters . 204 . 1 . 61–8 . February 2004 . 14744535 . 10.1016/j.canlet.2003.09.015 . 2433/147532 . free .
• Aoyama T, Okamoto T, Nagayama S, Nishijo K, Ishibe T, Yasura K, Nakayama T, Nakamura T, Toguchida J . Methylation in the core-promoter region of the chondromodulin-I gene determines the cell-specific expression by regulating the binding of transcriptional activator Sp3 . The Journal of Biological Chemistry . 279 . 27 . 28789–97 . July 2004 . 15107420 . 10.1074/jbc.M401273200 . free .

Notes and References

1. Shukunami C, Hiraki Y . Expression of cartilage-specific functional matrix chondromodulin-I mRNA in rabbit growth plate chondrocytes and its responsiveness to growth stimuli in vitro . Biochemical and Biophysical Research Communications. 249 . 3 . 885–90 . August 1998 . 9731231 . 10.1006/bbrc.1998.9233 .
2. Hiraki Y, Mitsui K, Endo N, Takahashi K, Hayami T, Inoue H, Shukunami C, Tokunaga K, Kono T, Yamada M, Takahashi HE, Kondo J . Molecular cloning of human chondromodulin-I, a cartilage-derived growth modulating factor, and its expression in Chinese hamster ovary cells . European Journal of Biochemistry . 260 . 3 . 869–78 . March 1999 . 10103018 . 10.1046/j.1432-1327.1999.00227.x . free .
3. Web site: Entrez Gene: LECT1 leukocyte cell derived chemotaxin 1.
4. Yoshioka M, Yuasa S, Matsumura K, Kimura K, Shiomi T, Kimura N, Shukunami C, Okada Y, Mukai M, Shin H, Yozu R, Sata M, Ogawa S, Hiraki Y, Fukuda K . Chondromodulin-I maintains cardiac valvular function by preventing angiogenesis . Nature Medicine . 12 . 10 . 1151–9 . October 2006 . 16980969 . 10.1038/nm1476 . 7704603 .