BNI4/YNL233W Summary Help

Standard Name BNI4 1
Systematic Name YNL233W
Feature Type ORF, Verified
Description Targeting subunit for Glc7p protein phosphatase; localized to the bud neck, required for localization of chitin synthase III to the bud neck via interaction with the chitin synthase III regulatory subunit Skt5p (2 and see Summary Paragraph)
Name Description Bud Neck Involved 1
Chromosomal Location
ChrXIV:211922 to 214600 | ORF Map | GBrowse
Gene Ontology Annotations All BNI4 GO evidence and references
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 3 genes
Classical genetics
Large-scale survey
212 total interaction(s) for 127 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 8
  • Affinity Capture-Western: 4
  • PCA: 1
  • Two-hybrid: 7

Genetic Interactions
  • Dosage Growth Defect: 5
  • Dosage Lethality: 5
  • Negative Genetic: 85
  • Phenotypic Enhancement: 1
  • Positive Genetic: 22
  • Synthetic Growth Defect: 24
  • Synthetic Lethality: 47
  • Synthetic Rescue: 3

Expression Summary
Length (a.a.) 892
Molecular Weight (Da) 100,589
Isoelectric Point (pI) 4.77
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXIV:211922 to 214600 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..2679 211922..214600 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000005177

BNI4 encodes a scaffold protein that tethers chitin synthase III (Chs3p) to the bud neck by interacting with septin neck filaments and with Skt5p, which is a regulatory subunit of chitin synthase III (2). Bni4p is also involved in targeting protein phosphatase 1 (Glc7p) to the bud neck before bud emergence (2). Bni4p is required for the assembly of the chitin ring, and is also involved in septum formation and the maintenance of bud neck integrity (3).

Bni4p localization is regulated during the cell cycle, with the protein located on the exterior of the septin ring before budding and on the mother side of the collar after budding (4). Proper localization of Bni4p requires the actin cytoskeleton, and binding to Glc7p, since cells containing mutant bni4 that fails to associate with Glc7p display mislocalization of Bni4p (2, 4). Bni4 is phosphorylated in a cell cycle-dependent manner, and inactivation of the protein kinase Hsl1p affects Bni4p localization, but there is no evidence that Hsl1p directly phosphorylates Bni4p (2).

bni4 null mutants are viable, but display altered deposition of chitin, and mislocalization of Chs3p, Skt5p, and Glc7p (3, 2).

Last updated: 2005-09-20 Contact SGD

References cited on this page View Complete Literature Guide for BNI4
1) DeMarini DJ, et al.  (1997) A septin-based hierarchy of proteins required for localized deposition of chitin in the Saccharomyces cerevisiae cell wall. J Cell Biol 139(1):75-93
2) Kozubowski L, et al.  (2003) A Bni4-Glc7 phosphatase complex that recruits chitin synthase to the site of bud emergence. Mol Biol Cell 14(1):26-39
3) Sanz M, et al.  (2004) Saccharomyces cerevisiae Bni4p directs the formation of the chitin ring and also participates in the correct assembly of the septum structure. Microbiology 150(Pt 10):3229-41
4) Kozubowski L, et al.  (2005) Role of the septin ring in the asymmetric localization of proteins at the mother-bud neck in Saccharomyces cerevisiae. Mol Biol Cell 16(8):3455-66