Homeobox protein Mohawk, also known asiroquois homeobox protein-like 1, is aprotein that in humans is encoded by theMKX (mohawk homeobox)gene.[5] MKX is a member of an Iroquois (IRX) family-related class of 'three-amino acid loop extension' (TALE) atypical homeobox proteins characterized by 3 additional amino acids in the loop region between helix I and helix II of the homeodomain.[5][6]
MKX is a transcription factor that regulates tendon differentiation during embryological development. Knocking out this gene in mouse embryos results in them developinghypoplastic tendons containing less type I collagen.[7] MKX binds directly to the promoter of MyoD and represses its expression, negatively regulating muscle differentiation.[8]
Expression of MKX is maintained in adult tendon tissues, decreasing as a result of ageing or osteoarthritis. Collagen fibres in tendons become more dense and thick following mechanical stimulation as a result of exercise,[9] and MKX is essential in this mechanosensory process.[10]
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Weinmann A, Galle PR, Teufel A (September 2005). "In silico characterization of an Iroquois family-related homeodomain protein".International Journal of Molecular Medicine.16 (3):443–8.doi:10.3892/ijmm.16.3.443.PMID16077953.
