Sugar-regulated control of alpha-tubulin in maize cell suspension culture

The data reported here shows that alpha -tubulin, the subunit of microtubul in in the cytoskeleton, is regulated by sugars. A 48-h sugar-depletion trea tment in EMS maize cell suspension culture medium led to a marked reduction in the levels of alpha -tubulin mRNA and protein. This response was revers ible; the addition of metabolizable sugars led to a rapid increase in the l evels of the alpha -tubulin transcript. Levels of alpha -tubulin protein al so increased, albeit gradually. Surprisingly, there was little or no effect of phosphate depletion and phosphate addition on alpha -tubulin expression . Furthermore, the data show that sugars modulate a co-regulation of alpha -tubulin and cell-wall invertase. We propose that microtubules might be a m ajor component of a sugar-signaling pathway that is regulated by, among oth er factors, cellular carbon metabolism.