Irisin and FNDC5 in retrospect An exercise hormone or a transmembrane receptor?
نویسنده
چکیده
FNDC5 (fibronectin domain-containing [protein] 5) was initially discovered and characterized by two groups in 2002. In 2011 FNDC5 burst into prominence as the parent of irisin, a small protein containing the fibronectin type III domain. Irisin was proposed to be secreted by skeletal muscle cells in response to exercise, and to circulate to fat tissue where it induced a transition to brown fat. Since brown fat results in dissipation of energy, this pathway is of considerable interest for metabolism and obesity. Here I review the original discoveries of FNDC5 and the more recent discovery of irisin. I note in particular three problems in the characterization of irisin: the antibodies used to detect irisin in plasma lack validity; the recombinant protein used to demonstrate activity in cell culture was severely truncated; and the degree of shedding of soluble irisin from the cell surface has not been quantitated. The original discovery proposing that FNDC5 may be a transmembrane receptor may deserve a new look.
منابع مشابه
Irisin and FNDC5 in retrospect
FNDC5 (fibronectin domain-containing [protein] 5) was initially discovered and characterized by two groups in 2002. In 2011 FNDC5 burst into prominence as the parent of irisin, a small protein containing the fibronectin type III domain. Irisin was proposed to be secreted by skeletal muscle cells in response to exercise, and to circulate to fat tissue where it induced a transition to brown fat. ...
متن کاملمعرفی هورمون ورزش (Irisin)
Introduction: Almost 15% of world populations suffer from obesity. Obesity and insulin resistance are the key pathogenesis risk factors of type 2 diabetes mellitus (T2DM) and cardiovascular disease. Exercise training can accelerate metabolism and help to prevent the obesity and diabetes through induction of Irisin and triggers conversion of white adipose tissue to brown adipose tissue. Metho...
متن کاملIrisin as an exercise-stimulated hormone binding crosstalk between organs.
Irisin is a newly discovered 112 amino acid residues' glycosylated protein hormone that was firstly found up-regulated by exercise-induced peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) and then play an important role in circulation so as to target other organs. It conducts many downstream events including osteoblast differentiation, nerve cell and β-cell regenera...
متن کاملThe structure of irisin reveals a novel intersubunit β-sheet fibronectin type III (FNIII) dimer: implications for receptor activation.
Irisin was recently identified as a putative myokine that is induced by exercise. Studies suggest that it is produced by cleavage of the FNDC5 (fibronectin domain-containing protein 5) receptor; irisin corresponds to the extracellular receptor ectodomain. Data suggesting that irisin stimulates white-to-brown fat conversion have led to the hypothesis that it does so by binding an unknown recepto...
متن کاملIrisin Is Elevated in Skeletal Muscle and Serum of Mice Immediately after Acute Exercise
Recent findings regarding the response of fibronectin type III domain-containing protein 5 (Fndc5) and irisin to exercise are partly controversial. While the 25 kDa form of Fndc5 can be observed in muscle and serum of different species, the ~12 kDa irisin band was not detectable up to now. The present study aimed to clarify whether irisin exists in its theoretical size of ~12 kDa in mice and if...
متن کامل