Centrin

[4] They are a type of protein that is essential and present in almost all eukaryotic cells and are found in the centrioles and pericentriolar lattice.

[6] Jeffrey Salisbury, who discovered centrin in the green algae, and his colleagues used RNA interference (RNAi) to reduce the levels of centrin-2 in human tissue culture cells.

He had proved that centrin was involved in centriole duplication in animal cells like seen in his previous work with algae.

[5] Centrins show calcium-sensitive contractile behavior and was identified before as a calcium sensing regulator of the centriole structure.

[11] The extra-centrosomal materials function is not yet fully understood by researchers yet but using cross linking found centrin does have an affinity for actin and the terminal portion of the HC.

[13] Centrins contain four helix-loop-helix features specifically made binding with calcium in the transitional region of the axoneme.

Cetn2 which is expressed within somatic cells
Centrin containing fibers presented in this electron micrograph of Chlamydomonas centrioles