NISER

1996-2001 : Ph.D. (Molecular Biology) National Institute of Immunology, J.N.U. Campus New Delhi 110 067, INDIA 

1994-1996 : M. Sc. (Biochemistry) 

Department of Biochemistry, Nagpur University, Nagpur, Maharashtra, INDIA

1991-1994 : B. Sc. (Microbiology, Biochemistry, Chemistry) 

Nagpur University, Nagpur, Maharashtra, INDIA

Molecular Genetic Study of Protein Biosynthesis

NIH Fellows Award for Research Excellence (NIH-FARE) for years 2005 and 2006.

• Ram, A.K., Mallik, M., Reddy, R.R. Suryawanshi, AR and Alone PV. Altered proteome in translation initiation fidelity defective eIF5G31R mutant causes oxidative stress and DNA damage. Sci Rep 12, 5033 (2022). https://doi.org/10.1038/s41598-022-08857-y
• Antony A C, Ram AK, Dutta K and Alone PV. Ribosomal mutation in helix 32 of 18S rRNA alters fidelity of eukaryotic translation start site selection. (2019) FEBS Lett.
• Antony A C and Alone PV. Fidelity of HIS4 start codon selection influences 3-amino-1,2,4-triazole sensitivity in GTPase activating protein function defective eIF5. (2018) J Genet. 97 (4): 953-964.
• Antony A C and Alone PV. Defect in the GTPase activating protein (GAP) function of eIF5 causes repression of GCN4 translation. (2017) Biochem Biophys Res Commun. 486 (4):1110-1115.
• Alone PV, Cao C and Dever TE. Translation initiation factor eIF2γ mutants alter start codon selection independent of Met-tRNAiMet binding. (2008) Mol Cell Biol. 28 (22): 6877-88.
• Alone PV and Garg LC. Secretory and GM1 receptor binding role of N-Terminal end of LTB in Vibrio Cholerae. (2008) Biochem Biophy Res Comm. 376 (4): 770-4.
• Alone PV, Malik G, Krishnan A and Garg LC. Deletion mutations in N-terminal α1 helix render heat labile enterotoxin B subunit susceptible to degradation. (2007) Proc Natl Acad Sci (USA). 104 (41): 16056-61
• Alone PV and Dever TE. Direct binding of translation initiation factor eIF2γ-G domain to its GTPase-activating and GDP-GTP exchange factors eIF5 and eIF2Bε. (2006) J Biol Chem. 281(18):12636-44.
• Roll-Mecak A, Alone P, Cao C, Dever TE and Burley SK. X-ray structure of translation initiation factor eIF2γ: implications for tRNA and eIF2α binding, (2004) J Biol Chem. 279 (11):10634-42.

The fundamental difference between prokaryotic and eukaryotic translation initiation is that the former uses Shine-Dalgarno (SD) sequence on the mRNA to recruit small ribosome subunit and locate AUG codon or rarely GUC, CUC or UUG codon as a translation start site, while the latter uses eIF4F complex to bind mRNA and locate AUG codon or rarely CUG, UUG or GUC as a start codon by 5` to 3` scanning mechanism. Some of the examples listed below shows the involvement of non-AUG codon as a translation start signal.

In Saccharomyces cerevisiae, GRS1 encodes two isoforms of Glycyl-tRNA synthetases, one initiates from upstream in-frame UUG codon (encoding signal sequence for mitochondrial import) while the regular cytoplasmic version initiates from downstream AUG codon. For the synthesis of Alanine t-RNA synthetase (ALA1) protein a consecutive ACG ACG codon are utilized as an alternate translation start site. It has been reported recently that MHC class-I molecule can load antigenic precursor which is synthesized by using CUG as an initiation codon recognized by leucine tRNA and non-conventional eIF2A translation initiation factor. A genome wide ribosomal profiling analysis of vivo translation study reported that translation initiation from upstream non-AUG codon is widespread in S. cerevisiae under starvation condition. However, the importance and the basic mechanism for these initiations are still unclear. A number of yeast mutants have been identified that are able to initiate at the non-AUG codons. These mutants were designated as Sui— (Suppressor of initiation) phenotypes. Sui— phenotypes are novel mutations that causes break down of AUG codon selection fidelity. Thus, Sui— mutants provide an important tool to understand the molecular mechanism of non-AUG codon selection.

The focus of our lab is to understand the molecular mechanism of non-canonical translation initiation processes in Saccharomyces cerevisiae using molecular genetic techniques.

The key questions are as follows:

• How Sui— mutants recognize UUG codon as a start codon?
• Does 18S rRNA residues play critical role in UUG codon recognition by Sui— mutant?
• Does cis-acting elements on mRNA plays critical role in non-AUG codon recognition by Sui— mutants?
• Are there special trans-acting factors involved in non-AUG codon selection?

• Molecular Biology (B304) for MSc students
• Molecular Biology Laboratory (B343) for MSc students
• Advance Molecular Biology (B551/B701) for MSc and Ph.D students