Tts1, the fission yeast homologue of the TMEM33 family, functions in NE remodeling during mitosis.
Bottom Line: An amphipathic helix located at the C-terminus of Tts1 is important for ER shaping and modulating the mitotic NPC distribution.Of interest, the evolutionarily conserved residues at the luminal interface of the third transmembrane region function specifically in promoting SPB-NE insertion.Our data illuminate cellular requirements for remodeling the NE during "closed" nuclear division and provide insight into the structure and functions of the eukaryotic TMEM33 family.
Affiliation: Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 email@example.com firstname.lastname@example.org.Show MeSH
Mentions: To examine mitotic spindle formation carefully, we performed time-lapse analyses of cells expressing fluorescent protein markers for the spindle (GFP-Atb2), the SPBs (Pcp1-mCherry), and the nucleoplasm (GST-NLS-mCherry) at 24°C. Wild type cells initiated bipolar spindle assembly within 3 min (2.5 ± 0.8 min, n = 11) after depolymerization of the interphase microtubule arrays (Figure 5A). tts1Δ cells assembled short spindles 2.8 ± 2.0 min (n = 18) after the depolymerization of cytoplasmic microtubules. However, in line with our immunofluorescence data, some tts1Δ cells went through a short but noticeable stage with microtubules forming small, aster-like structures (seven of 18 cells, indicated by an arrow in Figure 5A). All tts1Δ cells subsequently assembled bipolar spindles and completed mitosis.
Affiliation: Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 email@example.com firstname.lastname@example.org.