Calmodulin (CaM) (an abbreviation for CALcium-MODULated proteIN) is a calcium-binding messenger protein expressed in all eukaryotic cells. CaM is a multifunctional intermediate messenger protein that transduces calcium signals by binding calcium ions and then modifying its interactions with various target proteins.

CaM mediates many crucial processes such as inflammation, metabolism, apoptosis, smooth muscle contraction, intracellular movement, short-term and long-term memory, and the immune response. CaM is expressed in many cell types and can have different subcellular locations, including the cytoplasm, within organelles, or associated with the plasma or organelle membranes. Many of the proteins that CaM binds are unable to bind calcium themselves, and use CaM as a calcium sensor and signal transducer. CaM can also make use of the calcium stores in the endoplasmic reticulum, and the sarcoplasmic reticulum. CaM can undergo post-translational modifications, such as phosphorylation, acetylation, methylation and proteolytic cleavage, each of which has potential to modulate its actions.

Wang Kai (Chinese: 王锴; pinyin: Wáng Kǎi; born January 22, 1983 in Chongqing) is a Chinese football player who currently plays as a midfielder for Chengdu Blades .

Wang Kai started his football career playing for the Chongqing Lifan youth team before he was drafted into the senior team in the 2002 league season. The following seasons saw him gradually establish himself as an integral part of the team and would even go on to captain the side before the club were relegated in the 2006 league season. Wang Kai stayed loyal to the team and after two seasons in the second tier he had his personal best season when he scored ten goals in the 2008 league season to aid Chongqing back into the top tier.

Last update: March 11, 2011