The g-tubulin meshwork assists to the transport of cytosolic PCNA to chromatin in mammalian cells

Changes in the location of g-tubulin ensure cell survival and preserve genome integrity. We investigated whether the nuclear accumulation of g-tubulin facilitates the transport of proliferating cell nuclear antigen (PCNA) between the cytosolic and the nuclear compartment in mammalian cells. We found that the g-tubulin meshwork assists to the recruitment of PCNA to chromatin. Also, decreased levels of g-tubulin reduce the nuclear pool of PCNA. In addition, the g-tubulin C terminus encodes a PCNA-interacting peptide (PIP) motif, and a g-tubulin–PIP-mutant affects the nuclear accumulation of PCNA. In a cell-free system, PCNA and g-tubulin formed a complex. In tumors, there is a significant positive correlation between TUBG1 and PCNA expression. Thus, we report a novel mechanism that constitutes the basis for tumor growth by which the g-tubulin meshwork maintains indefinite proliferation by acting as an opportune scaffold for the transport of PCNA from the cytosol to the chromatin. Overall design: The experiment was preformed in one cell line and a total number of 22 samples were included.There are two samples for each antibody (gamma tubulin, macrohistone2A and PCNA). For gamma tubulin rhere is 2 samples for G0/G1, 0h, 3h, 5h, 7h, 9h and for MH2A and PCNA the timepoints are 3h and 5h and as control, there are 2 whole cell lysate (Input) samples included.