InnateDB: Systems Biology of the Innate Immune Response

Homo sapiens Protein: CHP1

Summary

InnateDB Protein

IDBP-6992.5

Last Modified

2014-10-13 [Report errors or provide feedback]

Gene Symbol

CHP1

Protein Name

Calcium-binding protein p22

Synonyms

CHP; p22; p24; Sid470p; SLC9A1BP;

Species

Homo sapiens

Ensembl Protein

ENSP00000335632

InnateDB Gene

IDBG-6990 (CHP1)

Protein Structure

UniProt Annotation

Function

Calcium-binding protein involved in different processes such as regulation of vesicular trafficking, plasma membrane Na(+)/H(+) exchanger and gene transcription. Involved in the constitutive exocytic membrane traffic. Mediates the association between microtubules and membrane-bound organelles of the endoplasmic reticulum and Golgi apparatus and is also required for the targeting and fusion of transcytotic vesicles (TCV) with the plasma membrane. Functions as an integral cofactor in cell pH regulation by controlling plasma membrane-type Na(+)/H(+) exchange activity. Affects the pH sensitivity of SLC9A1/NHE1 by increasing its sensitivity at acidic pH. Required for the stabilization and localization of SLC9A1/NHE1 at the plasma membrane. Inhibits serum- and GTPase-stimulated Na(+)/H(+) exchange. Plays a role as an inhibitor of ribosomal RNA transcription by repressing the nucleolar UBF1 transcriptional activity. May sequester UBF1 in the nucleoplasm and limit its translocation to the nucleolus. Associates to the ribosomal gene promoter. Acts as a negative regulator of the calcineurin/NFAT signaling pathway. Inhibits NFAT nuclear translocation and transcriptional activity by suppressing the calcium-dependent calcineurin phosphatase activity. Also negatively regulates the kinase activity of the apoptosis-induced kinase STK17B. Inhibits both STK17B auto- and substrate- phosphorylations in a calcium-dependent manner. {ECO:0000269PubMed:10593895, ECO:0000269PubMed:11350981, ECO:0000269PubMed:15035633, ECO:0000269PubMed:8901634}.

Subcellular Localization

Nucleus {ECO:0000250}. Cytoplasm {ECO:0000250}. Cytoplasm, cytoskeleton {ECO:0000250}. Membrane {ECO:0000250}. Endoplasmic reticulum-Golgi intermediate compartment {ECO:0000250}. Endoplasmic reticulum {ECO:0000250}. Cell membrane {ECO:0000269PubMed:11350981, ECO:0000269PubMed:15035633}. Note=Localizes in cytoplasmic compartments in dividing cells. Localizes in the nucleus in quiescent cells. Exported from the nucleus to the cytoplasm through a nuclear export signal (NES) and CRM1-dependent pathway. May shuttle between nucleus and cytoplasm. Localizes with the microtubule-organizing center (MTOC) and extends toward the periphery along microtubules. Associates with membranes of the early secretory pathway in a GAPDH-independent, N-myristoylation- and calcium-dependent manner. Colocalizes with the mitotic spindle microtubules. Colocalizes with GAPDH along microtubules. Colocalizes with SLC9A1/NHE1 at the reticulum endoplasmic. Colocalizes with STK17B at the plasma membrane (By similarity). Colocalizes with SLC9A1/NHE1 at the cell membrane. {ECO:0000250}.

Disease Associations

Tissue Specificity

Ubiquitously expressed. Has been found in fetal eye, lung, liver, muscle, heart, kidney, thymus and spleen. {ECO:0000269PubMed:8901634}.

Comments

Interactions

Number of Interactions

This gene and/or its encoded proteins are associated with 10 experimentally validated interaction(s) in this database.

Experimentally validated
Total	10 [view]
Protein-Protein	9 [view]
Protein-DNA	1 [view]
Protein-RNA	0
DNA-DNA	0
RNA-RNA	0
DNA-RNA	0

Gene Ontology

Molecular Function

Accession	GO Term
GO:0004860	protein kinase inhibitor activity
GO:0005215	transporter activity
GO:0005509	calcium ion binding
GO:0005515	protein binding
GO:0008017	microtubule binding
GO:0015459	potassium channel regulator activity
GO:0019900	kinase binding
GO:0048306	calcium-dependent protein binding

Biological Process

GO:0001578	microtubule bundle formation
GO:0001933	negative regulation of protein phosphorylation
GO:0006469	negative regulation of protein kinase activity
GO:0006611	protein export from nucleus
GO:0006813	potassium ion transport
GO:0007264	small GTPase mediated signal transduction
GO:0010923	negative regulation of phosphatase activity
GO:0017156	calcium ion-dependent exocytosis
GO:0022406	membrane docking
GO:0031122	cytoplasmic microtubule organization
GO:0031397	negative regulation of protein ubiquitination
GO:0031953	negative regulation of protein autophosphorylation
GO:0032088	negative regulation of NF-kappaB transcription factor activity
GO:0032417	positive regulation of sodium:proton antiporter activity
GO:0042308	negative regulation of protein import into nucleus
GO:0045056	transcytosis
GO:0050821	protein stabilization
GO:0051222	positive regulation of protein transport
GO:0051259	protein oligomerization
GO:0051453	regulation of intracellular pH
GO:0060050	positive regulation of protein glycosylation
GO:0061024	membrane organization
GO:0061025	membrane fusion
GO:0070885	negative regulation of calcineurin-NFAT signaling cascade
GO:0071468	cellular response to acidity
GO:0090314	positive regulation of protein targeting to membrane

Cellular Component

GO:0000139	Golgi membrane
GO:0005634	nucleus
GO:0005737	cytoplasm
GO:0005783	endoplasmic reticulum
GO:0005793	endoplasmic reticulum-Golgi intermediate compartment
GO:0005829	cytosol
GO:0005886	plasma membrane
GO:0015630	microtubule cytoskeleton
GO:0030133	transport vesicle
GO:0070062	extracellular vesicular exosome