High impact information on SPC72

• Thus, the SPB-associated Spc72-Stu2 complex plays a key role in regulating microtubule properties [1].
• We show that yeast Spc72 has two distinct domains involved in microtubule organization [1].
• XMAP215-related proteins also bind to centrosomes and spindle pole bodies (SPBs) through proteins like the mammalian transforming acidic coiled coil protein TACC or the yeast Spc72 [1].
• Interaction of the yeast gamma-tubulin complex-binding protein Spc72p with Kar1p is essential for microtubule function during karyogamy [2].
• This binding of Spc72p to Kar1p has only a minor role during vegetative growth, whereas it becomes essential for karyogamy in mating cells, explaining the important role of Kar1p in this process [2].

Biological context of SPC72

• Precisely, deletion of SPC72 resulted in a decreased number of astral microtubules: early in the cell cycle only few were detectable, and these were unattached to the spindle pole body in small-budded cells [3].
• SPC72 was found to be non-essential for cell growth, but its deletion resulted in abnormal spindle positioning, aberrant nuclear migration and defective mating capability [3].
• The chromosome segregation block does not arrest the cell cycle; instead, spc72 cells undergo cytokinesis, producing aploid cells and polyploid cells that contain multiple SPBs [4].

Anatomical context of SPC72

• In contrast, overexpression of the entire SPC72 results in more cytoplasmic microtubules compared with wild-type [5].
• However, SPC72 deletion is not lethal because elongated but misaligned spindles can frequently reorient in mother cells, permitting delayed but otherwise correct nuclear segregation [6].

Physical interactions of SPC72

• Here, we describe the identification of the essential SPB component Spc72p whose N-terminal domain interacts with the Tub4p complex on the cytoplasmic side of the SPB [5].
• The yeast spindle pole body component Spc72p interacts with Stu2p and is required for proper microtubule assembly [4].

Other interactions of SPC72

• We postulate that in cnm67Delta cells Spc72-gamma-tubulin complex-capped astral microtubules are released from the half-bridge upon SPB separation but fail to be anchored to the cytoplasmic side of the SPB because of the absence of an outer plaque [7].
• Spc72p is the yeast GTBP at the cytoplasmic side of the SPB, while Spc110p is the nuclear GTBP [8].

Analytical, diagnostic and therapeutic context of SPC72

• Immunoelectron microscopy confirmed that Spc72p was a component of these polymers [3].

References