Meiotic chromosome movement: what’s lamin got to do with it?

Abstract

Active meiotic chromosome movements are a universally conserved feature. They occur at the early stages of prophase of the first meiotic division and support the chromosome pairing process by (1) efficiently installing the synaptonemal complex between homologous chromosomes, (2) discouraging inadvertent chromosome interactions and (3) bringing homologous chromosomes into proximity. Chromosome movements are driven by forces in the cytoplasm, which are passed on to chromosome ends attached to the nuclear periphery by nuclear-membrane-spanning protein modules. In this extra view, we highlight our recent studies into the role of the nuclear lamina during this process to emphasize that it is a highly conserved structure in metazoans. The nuclear lamina forms a rigid proteinaceous network that underlies the inner nuclear membrane to provide stability to the nucleus. Misdemeanors of the nuclear lamina during meiosis has deleterious consequences for the viability and health of the offspring, highlighting the importance of a functional nuclear lamina during this cell cycle stage.Abbreviations: DSB: DNA double strand break; LEM: LAP2, Emerin, MAN1; LINC: LInker of the Nucleoskeleton and Cytoskeleton; RPM: rapid prophase movement; SUN/KASH: Sad1p, UNC-84/Klarsicht, ANC-1, Syne Homology

Yeast RNA exosome activity is necessary for maintaining cell wall stability through proper protein glycosylation

“…Exo − ( dis3-D551N ) mutant displays temperature sensitivity ( Dra̧zkowska et al. , 2013 ; Milbury et al. , 2019 ), so we wondered whether the cause is similar as for rrp6Δ .…”

A network of nuclear envelope proteins and cytoskeletal force generators mediates movements of and within nuclei throughoutCaenorhabditis elegansdevelopment

“…Blocking SUN-1 phosphorylation leads to chromosome entanglements, unpaired chromosomes, and embryonic lethality. [114][115][116] Thus, both LMN-1 and SUN-1 are regulated by kinases to facilitate rapid chromosome movements and homolog pairing in meiosis.…”

“…LMN-1 is reduced and more sensitive to detergent, making it more soluble, allowing rapid chromosome movements. 114,115 LMN-1 remodeling is regulated by CHK-2 and PLK-2 kinase activity; a phospho-mutant lmn-1 animal, with eight phosphorylation sites mutated, was resistant to detergent and led to significant delays in homolog pairing. 115 Additionally, the nucleoplasmic domain of SUN-1 is phosphoregulated by CHK-2 and PLK-2 during rapid chromosome movements.…”

Phosphorylation of luminal region of the SUN-domain protein Mps3 promotes nuclear envelope localization during meiosis

“…First, meiosis-specific components of the LINC complex, such as Ndj1 and Csm4, are expressed and incorporated. Ndj1 is a meiosis-specific telomere-binding protein necessary for telomere tethering to NEs (Chua & Roeder, 1997;Conrad, Dominguez, & Dresser, 1997), whereas Csm4 is a meiosis-specific ONM protein (Conrad, Lee, Wilkerson, & Dresser, 2007;Kosaka, Shinohara, & Shinohara, 2008;Wanat et al, 2008), which interacts with a unique class of KASH protein, Mps2 (Chen et al, 2019;Lee et al, 2020a). Second, actin cable formation is specifically induced in the cytoplasm of meiotic cells (Koszul et al, 2008;Taxis et al, 2006).…”

“…Third, NE dynamics, including NE remodelling and movement, occur prominently in meiotic prophase I (Conrad et al 2007;this paper). NE remodelling is accompanied by NE localisation of a yeast SUN-domain protein, Mps3/Nep98 (Conrad et al, 2007), and Mps2 (Lee et al, 2020a). During mitosis, Mps3 and Mps2 predominantly localise to SPB as a component of the half-bridge as well as SPB-interacting network (SPIN) (Chen et al, 2019) and play an essential role in SPB duplication (Jaspersen, Giddings, & Winey, 2002;Nishikawa et al, 2003).…”