A motor independent requirement for dynein light chain in Caenorhabditis elegans meiotic synapsis

• Published in: Genetics (Austin) Vol. 220; no. 1
• Main Authors: Fielder, Sara M, Kent, Tori, Ling, Huiping, Gleason, Elizabeth J, Kelly, William G
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 04.01.2022; Genetics Society of America
• Subjects: Animals; Binding; Caenorhabditis elegans; Caenorhabditis elegans - genetics; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - genetics; Caenorhabditis elegans Proteins - metabolism; Chains; Chromatin; Chromosome Pairing; Chromosomes; Depletion; Dynein; Dyneins - genetics; Dyneins - metabolism; Genetics; Heat resistance; High temperature; Homology; Investigation; Light chains; Meiosis; Mutation; Nematodes; Proteins; Recombination; Sc protein; Self-association; Synaptonemal complex; Synaptonemal Complex - genetics; Synaptonemal Complex - metabolism; Syp protein; Temperature requirements; meiotic synapsis; dynein light chain; meiosis; C. elegans
• ISSN: 1943-2631; 0016-6731; 1943-2631
• DOI: 10.1093/genetics/iyab203

Abstract The dynein motor complex is thought to aid in homolog pairing in many organisms by moving chromosomes within the nuclear periphery to promote and test homologous interactions. This precedes synaptonemal complex (SC) formation during homolog synapsis, which stabilizes homolog proximity during recombination. We observed that depletion of the dynein light chain (DLC-1) in Caenorhabditis elegans irreversibly prevents synapsis, causing an increase in off-chromatin formation of SC protein foci with increasing temperature. This requirement for DLC-1 is independent of its function in dynein motors, as SYP protein foci do not form with depletion of other dynein motor components. In contrast to normal SC-related structures, foci formed with DLC-1 depletion are resistant to dissolution with 1,6-hexanediol, similar to aggregates of SC proteins formed in high growth temperatures. Dynein light chains have been shown to act as hub proteins that interact with other proteins through a conserved binding motif. We identified a similar DLC-1 binding motif in the C. elegans SC protein SYP-2, and mutation of the putative motif causes meiosis defects that are exacerbated by elevated temperatures. We propose that DLC-1 acts as a pre-synapsis chaperone-like factor for SYP proteins to help regulate their self-association prior to the signals for SC assembly, a role that is revealed by its increased essentiality at elevated temperatures.