Home » The role of Targeting Protein for Xklp2 (TPX2) in nuclear assembly and organization. by Lori L. OBrien
The role of Targeting Protein for Xklp2 (TPX2) in nuclear assembly and organization. Lori L. OBrien

The role of Targeting Protein for Xklp2 (TPX2) in nuclear assembly and organization.

Lori L. OBrien

Published
ISBN : 9780549636076
NOOKstudy eTextbook
172 pages
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 About the Book 

The nuclear envelope is a dynamic structure that must be broken down and reassembled during every metazoan cell division. This disassembly allows the segregation of sister chromatids by cytoplasmic microtubules. However, the nuclear envelope must beMoreThe nuclear envelope is a dynamic structure that must be broken down and reassembled during every metazoan cell division. This disassembly allows the segregation of sister chromatids by cytoplasmic microtubules. However, the nuclear envelope must be rebuilt around the newly segregated chromosomes. This is a complex process that is still not well understood. Therefore, identification of molecules involved in rebuilding the elaborate nuclear architecture is important. Here, I define a role for the Targeting Protein for Xklp2 (TPX2) in nuclear assembly and function. I find that TPX2 depletion from Xenopus egg extracts results in small, misshapen nuclei. Despite their small size, these nuclei have complete nuclear envelopes and are fully functional. TPX2 interacts with LAP2, a protein required for proper nuclear lamina assembly, and is required for appropriate LAP2 targeting during nuclear assembly. In addition, TPX2 interacts with lamins, chromatin and actin and has integral roles in chromatin condensation and transcription. Because actin has many similar nuclear functions, I hypothesize that TPX2 organizes a nuclear network of actin that is important for nuclear assembly, condensation and transcription. To support this hypothesis, I find that TPX2 disruption in egg extracts leads to nuclear actin mislocalization and aggregation. Taken together these data implicate TPX2 as a regulator of nuclear architecture that is necessary for proper nuclear functioning.