Adiponectin, also referred as Acrp30, AdipoQ, apM1, and gelatin binding protein of 28 kD (GBP-28), is encoded by the ADIPOQ gene in humans.
Adiponectin contains 244 amino acids with a collagen-like domain at the N-terminal and a globular domain at the C-terminal.
The globular domain can be proteolytically truncated forming the globular adiponectin (gAdiponectin).
This globular domain resembles the structure of the complement C1q and the TNF-α superfamily.
Adiponectin exists in a wide range of homo-oligomers: a low-molecular weight (LMW) trimer, a medium molecular weight (MMW) hexamer, and a high molecular weight (HMW) multimer with little or no interconversion between the forms.
Females generally have higher HMW than males in proportion and absolute amounts.
Adiponectin has two receptors (adipoRs)-1 and -2.
AdipoR1 mRNA is detectable in skeletal muscle, spleen, lung, heart, kidney, and liver.
AdipoR2 is expressed in liver, but is also detectable in heart, lung, skeletal muscle, and kidney.