TY - GEN T1 - Paternal mitochondria from an rmd-2, rmd-3, rmd-6 triple mutant are properly positioned in the C. elegans zygote AU - Juanico, Iris Y AU - Meyer, Christina M AU - McCarthy, John E AU - Gong, Ting AU - McNally, Francis J DO - 10.17912/micropub.biology.000422 UR - http://beta.micropublication.org/journals/biology/micropub-biology-000422/ AB - RMD-1 was discovered as a cytoplasmic regulator of microtubule dynamics in C. elegans and several highly homologous proteins were inferred from the C. elegans and human genome sequences (Oishi et al., 2007). One of the human homologs, RMD-3/PTPIP51, has an N-terminal extension relative to other RMDs that targets it to the mitochondrial outer membrane and which binds the endoplasmic reticulum (ER) protein VAPB (De Vos et al., 2012). This interaction mediates tethering of mitochondria to the ER in human cells (Stoica et al., 2014). None of the C. elegans RMDs have sequence homology with the N-terminal extension found on human RMD-3/PTPIP51, however, C. elegans RMD-2 has an N-terminal extension relative to the other RMDs and this extension has potential to form a transmembrane helix as determined by TMpred release 25 (https://embnet.vital-it.ch/software/TMPRED_form.html). RMD-2 is present in sperm whereas RMD-3 and RMD-6 are highly enriched in sperm (Ma et al., 2014). Paternal mitochondria are eventually degraded in the embryo (Sato and Sato, 2011). However, they are maintained, along with other sperm contents, at the opposite end of the zygote from the female meiotic spindle during meiosis (Fig. 1). We hypothesized that RMD-2, 3 and 6 on paternal mitochondria bind to the VAPB homolog, VPR-1, on maternal ER at fertilization to tether the sperm contents at the future posterior end of the zygote. PY - 2021 JO - microPublication Biology ER -