HYP2/YEL034W Summary Help

Standard Name HYP2 1
Systematic Name YEL034W
Alias TIF51A 2
Feature Type ORF, Verified
Description Translation elongation factor eIF-5A; may function in translation initiation; structural homolog of bacterial EF-P; undergoes an essential hypusination modification; HYP2 has a paralog, ANB1, that arose from the whole genome duplication (3, 4, 5, 6, 7, 8, 9 and see Summary Paragraph)
Also known as: eIF5A , eIF-5A 2
Name Description HYPusine-containing protein 1
Chromosomal Location
ChrV:85676 to 86149 | ORF Map | GBrowse
Gbrowse
Gene Ontology Annotations All HYP2 GO evidence and references
  View Computational GO annotations for HYP2
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
High-throughput
Regulators 9 genes
Resources
Classical genetics
conditional
null
Large-scale survey
conditional
null
Resources
179 total interaction(s) for 155 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 71
  • Affinity Capture-RNA: 9
  • Affinity Capture-Western: 11
  • Co-fractionation: 1
  • Co-purification: 2
  • PCA: 2
  • Protein-RNA: 1
  • Reconstituted Complex: 1
  • Two-hybrid: 4

Genetic Interactions
  • Dosage Rescue: 22
  • Negative Genetic: 39
  • Positive Genetic: 6
  • Synthetic Growth Defect: 3
  • Synthetic Lethality: 6
  • Synthetic Rescue: 1

Resources
Expression Summary
histogram
Resources
Length (a.a.) 157
Molecular Weight (Da) 17,114
Isoelectric Point (pI) 4.64
Localization
Phosphorylation PhosphoGRID | PhosphoPep Database
Structure
Homologs
sequence information
ChrV:85676 to 86149 | ORF Map | GBrowse
This feature is contained within: YEL034C-A
SGD ORF map
Last Update Coordinates: 1996-07-31 | Sequence: 1996-07-31
Subfeature details
Relative
Coordinates
Chromosomal
Coordinates
Most Recent Updates
Coordinates Sequence
CDS 1..474 85676..86149 1996-07-31 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
Resources
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000000760
SUMMARY PARAGRAPH for HYP2

The paralogous genes HYP2 and ANB1 encode the translation elongation factor eIF-5A. The two gene products are 90% identical to each other (2). Because Hyp2p is expressed under normal, aerobic growth conditions while Anb1p is expressed only under anaerobic conditions, most functional studies have focused on Hyp2p (10, 2). However, since the two proteins are functionally interchangeable in vivo (3), results obtained with Hyp2p are likely to be directly applicable to Anb1p.

eIF-5A was long considered to be a translation initiation factor based on in vitro assays of certain aspects of translation; however, since some in vitro assays did not suggest a role in initiation, and since depletion of eIF-5A does not severely affect overall translation, its role was unclear (see 11, 8 for review). Since then, detailed studies of hyp2 conditional mutant phenotypes have revealed translational defects and alterations in polysome profiles characteristic of elongation factor mutations, as well as decreased accumulation of P-bodies, which is known to occur in elongation mutants (7, 8). HYP2 also displays synthetic genetic interactions with translation elongation factor mutants (7), and physical interaction with elongation factor eEF2 (Eft1p and Eft2p; 6). Furthermore, Hyp2p stimulates both translation elongation and termination in vitro (8). Thus, multiple lines of evidence are consistent with a primary role for eIF-5A in promoting translation elongation (7, 8).

eIF-5A is highly conserved across all species. The human ortholog EIF5A (OMIM) complements the inviability of the yeast hyp2 anb1 double null mutant (3). Both Hyp2p and Anb1p undergo the conversion of a single lysine residue to hypusine (N- epsilon-(4-amino-2-hydroxybutyl)-lysine), which is essential for function (12, 13). The modification is conserved among eIF-5A orthologs in eukaryotes and Archaea, and eIF-5A orthologs are the only known hypusinated proteins (14). eIF-5A orthologs in Eubacterial species, such as elongation factor P (EF-P), are not hypusinated (14). Hypusination of Hyp2p is essential for two kinds of protein-protein interactions in which it participates: homodimer formation; and binding to intact 80S ribosomes, with a preference for actively translating ribosomes (15, 16). Both Hyp2p and Anb1p are also phosphorylated on a serine residue, but this modification has no obvious effects on function (17, 18).

The hyp2 null mutant in strain W303 is inviable under standard (aerobic) conditions although growth is observed under anaerobic conditions due to ANB1 expression; conversely, the anb1 null mutant fails to grow under anaerobic conditions but has no apparent phenotype under aerobic conditions (10). The hyp2 null mutant is slow-growing, rather than inviable, under standard conditions in a different strain background (2). The hyp2 anb1 double null mutant is inviable under all conditions (2).

Last updated: 2009-08-31 Contact SGD

References cited on this page View Complete Literature Guide for HYP2
1) Wohl T, et al.  (1992) Chromosomal localization of the HYP2-gene in Saccharomyces cerevisiae and use of pulsed-field gel electrophoresis for detection of irregular recombination events in gene disruption experiments. Electrophoresis 13(9-10):651-3
2) Schnier J, et al.  (1991) Translation initiation factor 5A and its hypusine modification are essential for cell viability in the yeast Saccharomyces cerevisiae. Mol Cell Biol 11(6):3105-14
3) Schwelberger HG, et al.  (1993) Translation initiation factor eIF-5A expressed from either of two yeast genes or from human cDNA. Functional identity under aerobic and anaerobic conditions. J Biol Chem 268(19):14018-25
4) Valentini SR, et al.  (2002) Genetic interactions of yeast eukaryotic translation initiation factor 5A (eIF5A) reveal connections to poly(A)-binding protein and protein kinase C signaling. Genetics 160(2):393-405
5) Byrne KP and Wolfe KH  (2005) The Yeast Gene Order Browser: combining curated homology and syntenic context reveals gene fate in polyploid species. Genome Res 15(10):1456-61
6) Zanelli CF, et al.  (2006) eIF5A binds to translational machinery components and affects translation in yeast. Biochem Biophys Res Commun 348(4):1358-66
7) Gregio AP, et al.  (2009) eIF5A has a function in the elongation step of translation in yeast. Biochem Biophys Res Commun 380(4):785-90
8) Saini P, et al.  (2009) Hypusine-containing protein eIF5A promotes translation elongation. Nature 459(7243):118-21
9) Henderson A and Hershey JW  (2011) Eukaryotic translation initiation factor (eIF) 5A stimulates protein synthesis in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 108(16):6415-9
10) Wohl T, et al.  (1993) The HYP2 gene of Saccharomyces cerevisiae is essential for aerobic growth: characterization of different isoforms of the hypusine-containing protein Hyp2p and analysis of gene disruption mutants. Mol Gen Genet 241(3-4):305-11
11) Merrick W  (2009) Translation: Till termination us do part. Nature 459(7243):44-5
12) Park MH  (2006) The post-translational synthesis of a polyamine-derived amino acid, hypusine, in the eukaryotic translation initiation factor 5A (eIF5A). J Biochem (Tokyo) 139(2):161-9
13) Dias CA, et al.  (2008) Structural modeling and mutational analysis of yeast eukaryotic translation initiation factor 5A reveal new critical residues and reinforce its involvement in protein synthesis. FEBS J 275(8):1874-88
14) Wolff EC, et al.  (2007) Posttranslational synthesis of hypusine: evolutionary progression and specificity of the hypusine modification. Amino Acids 33(2):341-50
15) Gentz PM, et al.  (2009) Dimerization of the yeast eukaryotic translation initiation factor 5A requires hypusine and is RNA dependent. FEBS J 276(3):695-706
16) Jao DL and Chen KY  (2006) Tandem affinity purification revealed the hypusine-dependent binding of eukaryotic initiation factor 5A to the translating 80S ribosomal complex. J Cell Biochem 97(3):583-98
17) Kang HA, et al.  (1993) Translation initiation factor eIF-5A, the hypusine-containing protein, is phosphorylated on serine in Saccharomyces cerevisiae. J Biol Chem 268(20):14750-6
18) Klier H, et al.  (1993) Determination and mutational analysis of the phosphorylation site in the hypusine-containing protein Hyp2p. FEBS Lett 334(3):360-4