TY - JOUR

T1 - The role of Patronin in Drosophila mitosis

AU - Pavlova, Gera A.

AU - Razuvaeva, Alyona V.

AU - Popova, Julia V.

AU - Andreyeva, Evgeniya N.

AU - Yarinich, Lyubov A.

AU - Lebedev, Mikhail O.

AU - Pellacani, Claudia

AU - Bonaccorsi, Silvia

AU - Somma, Maria Patrizia

AU - Gatti, Maurizio

AU - Pindyurin, Alexey V.

N1 - Publisher Copyright: © 2019 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2019/4/17

Y1 - 2019/4/17

N2 - Background: The calmodulin-regulated spectrin-associated proteins (CAMSAPs) belong to a conserved protein family, which includes members that bind the polymerizing mcrotubule (MT) minus ends and remain associated with the MT lattice formed by minus end polymerization. Only one of the three mammalian CAMSAPs, CAMSAP1, localizes to the mitotic spindle but its function is unclear. In Drosophila, there is only one CAMSAP, named Patronin. Previous work has shown that Patronin stabilizes the minus ends of non-mitotic MTs and is required for proper spindle elongation. However, the precise role of Patronin in mitotic spindle assembly is poorly understood. Results: Here we have explored the role of Patronin in Drosophila mitosis using S2 tissue culture cells as a model system. We show that Patronin associates with different types of MT bundles within the Drosophila mitotic spindle, and that it is required for their stability. Imaging of living cells expressing Patronin-GFP showed that Patronin displays a dynamic behavior. In prometaphase cells, Patronin accumulates on short segments of MT bundles located near the chromosomes. These Patronin "seeds" extend towards the cell poles and stop growing just before reaching the poles. Our data also suggest that Patronin localization is largely independent of proteins acting at the MT minus ends such as Asp and Klp10A. Conclusion: Our results suggest a working hypothesis about the mitotic role of Patronin. We propose that Patronin binds the minus ends within MT bundles, including those generated from the walls of preexisting MTs via the augmin-mediated pathway. This would help maintaining MT association within the mitotic bundles, thereby stabilizing the spindle structure. Our data also raise the intriguing possibility that the minus ends of bundled MTs can undergo a limited polymerization.

AB - Background: The calmodulin-regulated spectrin-associated proteins (CAMSAPs) belong to a conserved protein family, which includes members that bind the polymerizing mcrotubule (MT) minus ends and remain associated with the MT lattice formed by minus end polymerization. Only one of the three mammalian CAMSAPs, CAMSAP1, localizes to the mitotic spindle but its function is unclear. In Drosophila, there is only one CAMSAP, named Patronin. Previous work has shown that Patronin stabilizes the minus ends of non-mitotic MTs and is required for proper spindle elongation. However, the precise role of Patronin in mitotic spindle assembly is poorly understood. Results: Here we have explored the role of Patronin in Drosophila mitosis using S2 tissue culture cells as a model system. We show that Patronin associates with different types of MT bundles within the Drosophila mitotic spindle, and that it is required for their stability. Imaging of living cells expressing Patronin-GFP showed that Patronin displays a dynamic behavior. In prometaphase cells, Patronin accumulates on short segments of MT bundles located near the chromosomes. These Patronin "seeds" extend towards the cell poles and stop growing just before reaching the poles. Our data also suggest that Patronin localization is largely independent of proteins acting at the MT minus ends such as Asp and Klp10A. Conclusion: Our results suggest a working hypothesis about the mitotic role of Patronin. We propose that Patronin binds the minus ends within MT bundles, including those generated from the walls of preexisting MTs via the augmin-mediated pathway. This would help maintaining MT association within the mitotic bundles, thereby stabilizing the spindle structure. Our data also raise the intriguing possibility that the minus ends of bundled MTs can undergo a limited polymerization.

KW - Asp

KW - Augmin

KW - CAMSAP proteins

KW - Dgt6

KW - Drosophila

KW - Klp10A

KW - Microtubules

KW - Mitosis

KW - Patronin

KW - S2 cells

KW - COMPLEX

KW - CENTROSOME

KW - MICROTUBULE ORGANIZATION

KW - COOPERATE

KW - DYNAMICS

KW - MITOTIC SPINDLE

KW - PROTEIN ASP

KW - MINUS-END

KW - NUCLEATION

KW - GAMMA-TUBULIN

UR - http://www.scopus.com/inward/record.url?scp=85066488033&partnerID=8YFLogxK

U2 - 10.1186/s12860-019-0189-0

DO - 10.1186/s12860-019-0189-0

M3 - Article

C2 - 31284878

AN - SCOPUS:85066488033

VL - 20

SP - 7

JO - BMC Molecular and Cell Biology

JF - BMC Molecular and Cell Biology

SN - 2661-8850

IS - Suppl 1

M1 - 7

ER -