Paradiplonema papillatum CENPA-V5 IP

ABSTRACT: Transmission of genetic material from one generation to the next is a fundamental feature of all living cells. In eukaryotes, a macromolecular complex called the kinetochore plays crucial roles in this process by providing linkage between chromosomes and spindle microtubules. Little is known about this process in evolutionarily diverse protists. Within the supergroup Discoba, Eeuglenozoans forms a highly diversespeciose group of unicellular flagellates -including kinetoplastids, euglenids, and diplonemids. Kinetoplastids have an unconventional kinetochore system, while euglenids have a canonical onekinetochore system. It remains unclear what kind of kinetochores are present in diplonemids, a group of extremely diverse and abundant marine flagellatesplankton. Here, we employed deep homology detection protocols using profile-versus-profile Hidden Markov Model searches and AlphaFold-based structural comparisons to detect homologies that might have been previously missed. Interestingly, we still could not detect orthologs for most of the kinetoplastid nor canonical kinetochore subunits with few exceptions including a putative centromere-specific histone H3 variant (cenH3/CENP-A), the spindle checkpoint protein Mad2, the chromosomal passenger complex members Aurora and INCENP, and broadly conserved proteins like the CLK kinase and the meiotic synaptonemal complex proteins SYCP2 that function at kinetoplastid kinetochores. We examined the localization of five candidate kinetochore-associated proteins in the model diplonemid, Paradiplonema papillatum. PpCENP-A shows discrete dots in the nucleus, implying that it is likely a kinetochore component. PpMad2, PpCLK, PpSYCP2L1 and INCENP reside in the nucleus, but no clear kinetochore localization was observed. Altogether, these results raise a possibility that diplonemids evolved a hitherto unknown type of kinetochore system.

INSTRUMENT(S): Orbitrap Exploris 480

ORGANISM(S): Diplonema Papillatum

SUBMITTER: Corinna Benz  

LAB HEAD: Julius Lukes

PROVIDER: PXD054535 | Pride | 2024-10-21

REPOSITORIES: Pride