Foyt H L, Means A R
J Cyclic Nucleotide Protein Phosphor Res. 1985;10(2):143-55.
A phosphorylation occurs at two sites in chicken gizzard myosin light chain kinase that appears to be catalyzed by an autophosphorylation reaction. This reaction is inhibited by approximately 75% in the presence of Ca2+-calmodulin, but is unaffected by the cAMP-dependent protein kinase inhibitor. Whereas the catalytic subunit of cAMP-dependent protein kinase phosphorylates myosin light chain kinase at only serine residues, the non cAMP-dependent phosphorylation occurs at both serine and threonine residues. One, if not both, of these latter sites are distinct from the sites recognized by the catalytic subunit of cAMP-dependent protein kinase. Consequently, there must be at least three and possibly four sites in myosin light chain kinase capable of incorporating phosphate, either in response to catalytic subunit or by autophosphorylation.
鸡砂囊肌球蛋白轻链激酶中有两个位点发生磷酸化，这似乎是由自身磷酸化反应催化的。在Ca2 + -钙调蛋白存在的情况下，该反应被抑制约75%，但不受cAMP依赖性蛋白激酶抑制剂的影响。虽然cAMP依赖性蛋白激酶的催化亚基仅在丝氨酸残基上使肌球蛋白轻链激酶磷酸化，但非cAMP依赖性磷酸化发生在丝氨酸和苏氨酸残基上。这些后一种位点中的一个（如果不是两个）与cAMP依赖性蛋白激酶催化亚基识别的位点不同。因此，肌球蛋白轻链激酶中必须至少有三个且可能有四个位点能够结合磷酸，要么响应催化亚基，要么通过自身磷酸化。
