Tubulin Polymerization Promoting Proteins (TPPPs): Members of a New Family with Distinct Structures and Functions
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- 作者：Orsolya Vincze ; Natá ; lia Tö ; ké ; si ; Judit Olá ; h ; Emma Hlavanda ; Á ; gnes Zotter ; Istvá ; n Horvá ; th ; Attila Lehotzky ; Lá ; szló ; Tiriá ; n ; Katalin F.
- 刊名：Biochemistry
- 出版年：2006
- 出版时间：November 21, 2006
- 年：2006
- 卷：45
- 期：46
- 页码：13818 - 13826
- 全文大小：734K
- 年卷期：v.45,no.46(November 21, 2006)
- ISSN：1520-4995
文摘
TPPP/p25 is a brain-specific protein, which induces tubulin polymerization and microtubule(MT) bundling and is enriched in Lewy bodies characteristic of Parkinson's disease [Tiri
n et al. (2003)Proc. Natl. Acad. Sci. U.S.A. 100, 13976-13981]. We identified two human gene sequences, CG1-38and p25
ddle">, which encoded homologous proteins, that we termed p20 and p18, respectively. Thesehomologous proteins display 60% identity with tubulin polymerization promoting protein/p25 (TPPP/p25); however, the N-terminal segment of TPPP/p25 is missing. They could be clustered into threesubfamilies present in mammals and other vertebrates. We cloned, isolated, and characterized the structuraland functional properties of the recombinant human proteins at molecular, ultrastructural, and cellularlevels using a number of tools. These data revealed that, while p20 behaved as a disorganized proteinsimilarly to TPPP/p25, which was described as a flexible and inherently dynamic protein with a longunstructured N-terminal tail, p18 was featured in more ordered fashion. TPPP/p25 and p20 specificallyattached to MTs causing MT bundling both in vitro and in vivo; p18 protein did not cross-link MTs, andit distributed homogeneously within the cytosol of the transfected HeLa cells. These data indicate that thetwo shorter homologues display distinct structural features that determine their associations to MTs. Theproperties of p20 resemble TPPP/p25. The bundling activity of these two proteins results in the stabilizationof the microtubular network, which is likely related to their physiological functions.
n et al. (2003)Proc. Natl. Acad. Sci. U.S.A. 100, 13976-13981]. We identified two human gene sequences, CG1-38and p25ddle">, which encoded homologous proteins, that we termed p20 and p18, respectively. Thesehomologous proteins display 60% identity with tubulin polymerization promoting protein/p25 (TPPP/p25); however, the N-terminal segment of TPPP/p25 is missing. They could be clustered into threesubfamilies present in mammals and other vertebrates. We cloned, isolated, and characterized the structuraland functional properties of the recombinant human proteins at molecular, ultrastructural, and cellularlevels using a number of tools. These data revealed that, while p20 behaved as a disorganized proteinsimilarly to TPPP/p25, which was described as a flexible and inherently dynamic protein with a longunstructured N-terminal tail, p18 was featured in more ordered fashion. TPPP/p25 and p20 specificallyattached to MTs causing MT bundling both in vitro and in vivo; p18 protein did not cross-link MTs, andit distributed homogeneously within the cytosol of the transfected HeLa cells. These data indicate that thetwo shorter homologues display distinct structural features that determine their associations to MTs. Theproperties of p20 resemble TPPP/p25. The bundling activity of these two proteins results in the stabilizationof the microtubular network, which is likely related to their physiological functions.