Distinctive features of plant protein kinase CK2

In plants, protein kinase CK2 is involved in different processes that contr ol many aspects of metabolism and development. In mammals and yeast the enz yme is a heterotretamer composed of two types of subunits. During years the subunit composition of the maize protein kinase CK2 enzyme has been a sour ce of controversy. We have recently characterized the maize holoenzyme subu nits. Our results show that multiple catalytic and regulatory subunits are expressed in maize and are able to specifically interact with other alpha a nd beta subunits suggesting a high level of heterogeneity in the typical he terotetrameric structure. Here, we summarize data available on plant CK2 en zymes, in order to clarify the distinctive features and functions of plant protein kinase CK2.