Files and links (1)
CC BY V4.0, Open Access
Thesis
PDX PROTEINS FROM ARABIDOPSIS THALIANA AS NOVEL SUBSTRATES OF CATHEPSIN B: IMPLICATIONS FOR VITAMIN B6 BIOSYNTHESIS REGULATION
Master of Science (MS), Washington State University
2025
Abstract
Vitamin B6 (vitB6) is an important molecule that is critical for metabolism and development in plants. It is a cofactor for a plethora of biochemical reactions that regulate basic cellular function and physiology. Plants can synthesize vitB6 de novo with only two proteins: Pyridoxine Biosynthesis Protein 1(PDX1) and PDX2. VitB6 biosynthesis in plants is well understood, but there are still many open questions in terms of regulatory mechanisms. Because of the central role of the vitamin in cellular metabolism, it is likely that the biosynthesis of vitB6 is highly regulated. One such regulatory mechanism that may impact the rate of vitB6 production is protein proteolysis. There are several ways proteins can be degraded, including the Ubiquitin Proteasome Pathway (UPP) and the autophagy pathway. This work demonstrates that PDX proteins are unstable in a UPP-independent manner. In addition, it shows that cathepsin B, a cysteine protease connected to autophagy, is a novel PDX interactor that facilitates PDX degradation, two novel findings that connect cathepsin activities with vitB6 biosynthesis. This work will discuss the implications of these findings, as well as what is known about vitB6 and PDX proteins in general, including broader applications.
Metrics
1 Record Views
Details
- Title
- PDX PROTEINS FROM ARABIDOPSIS THALIANA AS NOVEL SUBSTRATES OF CATHEPSIN B: IMPLICATIONS FOR VITAMIN B6 BIOSYNTHESIS REGULATION
- Creators
- Marcelina E Parra
- Contributors
- Hanjo Hellmann (Advisor)Mechthild Tegeder (Committee Member)Sanja Roje (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- School of Biological Sciences
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Number of pages
- 116
- Identifiers
- 99901356785001842
- Language
- English
- Resource Type
- Thesis