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Rab2 GTPase regulates vesicle trafficking between the endoplasmic reticulum and the Golgi bodies and is important to pollen tube growth.
- Source :
-
The Plant cell [Plant Cell] 2002 Apr; Vol. 14 (4), pp. 945-62. - Publication Year :
- 2002
-
Abstract
- Pollen tube elongation depends on the secretion of large amounts of membrane and cell wall materials at the pollen tube tip to sustain rapid growth. A large family of RAS-related small GTPases, Rabs or Ypts, is known to regulate both anterograde and retrograde trafficking of transport vesicles between different endomembrane compartments and the plasma membrane in mammalian and yeast cells. Studies on the functional roles of analogous plant proteins are emerging. We report here that a tobacco pollen-predominant Rab2, NtRab2, functions in the secretory pathway between the endoplasmic reticulum and the Golgi in elongating pollen tubes. Green fluorescent protein-NtRab2 fusion protein localized to the Golgi bodies in elongating pollen tubes. Dominant-negative mutations in NtRab2 proteins inhibited their Golgi localization, blocked the delivery of Golgi-resident as well as plasmalemma and secreted proteins to their normal locations, and inhibited pollen tube growth. On the other hand, when green fluorescent protein-NtRab2 was over-expressed in transiently transformed leaf protoplasts and epidermal cells, in which NtRab2 mRNA have not been observed to accumulate to detectable levels, these proteins did not target efficiently to Golgi bodies. Together, these observations indicate that NtRab2 is important for trafficking between the endoplasmic reticulum and the Golgi bodies in pollen tubes and may be specialized to optimally support the high secretory demands in these tip growth cells.
- Subjects :
- Biological Transport
Gene Expression Regulation, Plant
Green Fluorescent Proteins
Luminescent Proteins genetics
Luminescent Proteins metabolism
Microscopy, Electron
Mutation
Plant Leaves genetics
Plant Leaves metabolism
Plants, Genetically Modified
Pollen genetics
Pollen ultrastructure
Recombinant Fusion Proteins genetics
Recombinant Fusion Proteins metabolism
Nicotiana genetics
rab2 GTP-Binding Protein genetics
Endoplasmic Reticulum metabolism
Golgi Apparatus metabolism
Pollen growth & development
Nicotiana metabolism
rab2 GTP-Binding Protein physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1040-4651
- Volume :
- 14
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- The Plant cell
- Publication Type :
- Academic Journal
- Accession number :
- 11971147
- Full Text :
- https://doi.org/10.1105/tpc.000836