BAALC

Last updated
brain and acute leukemia, cytoplasmic
Identifiers
SymbolBAALC
NCBI gene 79870
HGNC 14333
OMIM 606602
RefSeq NP_079088.1 NP_001019543.1 NP_079088.1
UniProt Q8WXS3
Other data
Locus Chr. 8 q22.3
Search for
Structures Swiss-model
Domains InterPro

BAALC is a gene that codes for the brain and acute leukemia cytoplasmic protein. [1] The official symbol (BAALC) and official name (brain and acute leukemia cytoplasmic) is maintained by the HGNC. [2] The function of BAALC is not fully understood yet, but has been suggested to have synaptic roles involving the post synaptic lipid raft. [3] Lipid rafts are microdomains that are enriched with cholesterol and sphingolipids, lipid raft functions include membrane trafficking, signal processing, and regulation of the actin cytoskeleton. [3] The postsynaptic lipid raft possesses many proteins and is one of the major sites for signal processing and postsynaptic density (PSD). [3] Along with its involvement in the post synaptic lipid rafts, BAALC expression has been associated with Acute Lymphoblastic Leukemia and Acute Myeloid Leukemia. [1]

Contents

Genetics

Location of BAALC is 8q22.3 Ideogram human chromosome 8.svg
Location of BAALC is 8q22.3
8q22.3 marked, this showing the location of BAALC gene BAALC Gene on Chromosome 8.png
8q22.3 marked, this showing the location of BAALC gene

BAALC gene is located on the long arm (q) of chromosome 8 at position 22.3 (8q22.3). [4] The human BAALC gene contains eight exons, spans 89 613 bases of genomic DNA, and the transcript contains 180 amino acids. [4] [5]

The BAALC gene is highly conserved in mammals, domestic pigs, mice and rats. [1] But BAALC is not seen in lower organisms such as: Drosophila. melanogaster, Saccharomyces. cerevisiae, and Caenorhabditis. elegans . [1]

BAALC and its protein are expressed highly in neural tissues such as the Central Nervous System (CNS) and the Spinal Cord, and less expressed in neuroectodermal-derived tissues like the adrenal glands. [1] The BAALC protein is not expressed in peripheral blood leukocytes (PBL), lymph nodes, or nonneural tissues. [1] [4] BAALC expression has only been found in Bone Marrow (BM) when expressed from CD34+ progenitor cells, besides this BAALC expression has not been visualized. [1] The expression of BAALC from the CD34+ progenitor cells suggest the gene has neuroectodermal and hematopoietic cell functions. [6] [1] [7] BAALC expression is higher in neuroectodermal-derived tissues such as the frontal part of the brain, more specifically in the hippocampus, and neocortex. [3]

The BAALC gene has eight different transcripts that result into six different protein isoforms. [8] Isoforms that carry the exon number two do not express protein and it is believed that the termination in exon two results in an unstable protein after translation. [1] The isoforms 1-6-8 and 1-8 are neuroectodermal isoforms and these are highly conserved in the above-mentioned mammals. [1]

Function

The BAALC gene initially was discovered in the neuroderm of both the human and the mouse. [1] The function of BAALC protein is not understood very well, but it is predicted to be associated with the cytoskeleton network. [1] When expressed in Bone Marrow CD34+ progenitor cells, BAALC has neuroectodermal and hematopoietic cell functions. [1] Differentiation failure caused by cell shape, motility and adhesion in association between cells are all possible outcomes due to the little known effects and unclear mechanism sites of the BAALC genes. [7] The role of the BAALC gene causing leukemia in immature acute leukemic cells has been found by knocking out the function of BAALC gene using hairpin (stem loop) RNA in a human leukemia cell line KG1a. [9] The result of knocking out BAALC expression is a decrease in uncontrolled cell growth and an increase in programmed cell death. [9] [7] The BAALC protein isoform 1-6-8, has been found to interact and associate with the CAMKII alpha subunit and not with the beta subunit. [3] The interaction with the CAMKII alpha subunit is in the CAMKII protein's regulatory region and near the autophosphorylation site, this suggested a regulatory function of the 1-6-8 isoform on the alpha subunit. [3] BAALC 1-6-8 isoform also gets targeted to post synaptic lipid rafts, which are thought to have functions involved in: signal processing, membrane trafficking, and regulation of the actin cytoskeleton. [3] BAALC may play a role in the regulation of the CAMKII protein through interactions with the alpha subunit, no interactions have been found with the beta subunit of this protein. [3] Evidence has shown the BAALC protein to be an intracellular protein with cytoskeleton network roles, these roles include regulation of the actin cytoskeleton which is an associated role of postsynaptic lipid rafts. [1] [3]

Clinical significance

In studies it has been found that overexpression of BAALC is seen in 28% of people with AML and 65% of people with ALL. [1] BAALC is ruled out as a marker for neoplasia because it is not expressed in other cancer cells. [1] BAALC is seen in acute leukemia in immature myoblasts and early progenitor cells, but is excluded from mature hematopoietic cells. [9] [1] It has been found in studies that acute myeloid leukemia patients who over expressed BAALC (BAALC Positive) had a median of approximately 5 months of event free survival, but those who were BAALC negative had a median of around 15 months. [1] Research has found when BAALC is combined with the oncogene Hoxa9, BAALC blocks myeloid differentiation. [10] This blocking induces leukemogenesis. BAALC over-expression is associated with IDH1 and IDH2 wild type in Chinese cytogenetically normal acute myeloid leukemia patients. [10] The results found by Zhou et al. are different than that found by Weber et al. where no difference in mutations in IDH1 and IDH2 were seen depending on expression of BAALC. [9] IGFBP7 is another gene involved in leukemia, this was found conducting gene expression profiles (GEP) with BAALC. [10] This gene has BAALC characteristics and, unlike BAALC, may have a role in drug resistance and the mechanism of leukemogenesis. [10] It has been found that treatment for some acute leukemias failed due to BAALC and this suggests BAALC to be a potential surrogate marker. [10] The use of BAALC expression in acute leukemia prognosis is unclear and being studied. [7] [6] The prognosis of patients with AML and BAALC over-expression has been found to be poor or worse than poor. [7] Over-expression of the BAALC gene and considerable accumulation of the gene production has been found to have caused drug resistance in patients. [7]

Expression in Cancers

CancerUnder or Over expressionEvaluation MethodReference
Acute Myeloid Leukemia (AML)Over Expression RT-PCR [1]
Acute Lymphoblastic Leukemia (ALL)Over ExpressionRT-PCR [1]

Overexpression of the BAALC gene is seen in Acute Myeloid Leukemia (AML) and Acute Lymphoblastic Leukemia (ALL). [10] [11] It has been found that BAALC can cause the start of Leukemia (leukemogenesis) by stopping the differentiation of myeloid. [12] Silencing BAALC lowers the amount of proliferation and increased cell death (apoptosis) in leukemic cell lines KG1a [9] It has also been found with the over-expression of the BAALC genes to cause low levels of complete remission in cancer patients, and low amount of overall survival in patients. [7]

Structure

The human BAALC gene contains eight exons, spans 89 613 bases of genomic DNA, and the transcript contains 180 amino acids. [4] [5] This gene codes for eight different transcripts that are translated into six different protein isoforms. [1] [8] Isoforms containing exon number two (1-2-6-8 and 1-2-5-6-8) do not code protein and so exon two contains a termination codon. [1] The isoforms 1-6-8 and 1-8 are neuroectodermal isoforms and these are highly conserved in mammals. [1]

BAALC protein isoform 1-6-8 is modified by myristoylation and palmitoylation at the N-terminal. [3] These modifications occur on the Glycine 2 and Cysteine 3 amino acids of the protein. [3] These modifications are used for targeting the protein to the lipid rafts. [3] Little phosphorylation of the BAALC isoform 1-6-8 by the CAMK2A protein has been found as well. [3]

Interactions

CAMK2A [5] [4]

See also

CAMK2A [3]

Acute Myeloid Leukemia [1]

Acute lymphoblastic Leukemia [1]

CD34 [1]

IGFBP7 [10]

Related Research Articles

<span class="mw-page-title-main">Philadelphia chromosome</span> Genetic abnormality in leukemia cancer cells

The Philadelphia chromosome or Philadelphia translocation (Ph) is a specific genetic abnormality in chromosome 22 of leukemia cancer cells. This chromosome is defective and unusually short because of reciprocal translocation, t(9;22)(q34;q11), of genetic material between chromosome 9 and chromosome 22, and contains a fusion gene called BCR-ABL1. This gene is the ABL1 gene of chromosome 9 juxtaposed onto the breakpoint cluster region BCR gene of chromosome 22, coding for a hybrid protein: a tyrosine kinase signaling protein that is "always on", causing the cell to divide uncontrollably by interrupting the stability of the genome and impairing various signaling pathways governing the cell cycle.

<span class="mw-page-title-main">PTPRC</span> Mammalian protein found in Homo sapiens

Protein tyrosine phosphatase, receptor type, C also known as PTPRC is an enzyme that, in humans, is encoded by the PTPRC gene. PTPRC is also known as CD45 antigen, which was originally called leukocyte common antigen (LCA).

<span class="mw-page-title-main">Acute myeloblastic leukemia with maturation</span> Medical condition

Acute myeloblastic leukemia with maturation (M2) is a subtype of acute myeloid leukemia (AML).

<span class="mw-page-title-main">ETV6</span> Protein-coding gene in the species Homo sapiens

ETV6 protein is a transcription factor that in humans is encoded by the ETV6 gene. The ETV6 protein regulates the development and growth of diverse cell types, particularly those of hematological tissues. However, its gene, ETV6 frequently suffers various mutations that lead to an array of potentially lethal cancers, i.e., ETV6 is a clinically significant proto-oncogene in that it can fuse with other genes to drive the development and/or progression of certain cancers. However, ETV6 is also an anti-oncogene or tumor suppressor gene in that mutations in it that encode for a truncated and therefore inactive protein are also associated with certain types of cancers.

<span class="mw-page-title-main">EMR2</span> Protein-coding gene in the species Homo sapiens

EGF-like module-containing mucin-like hormone receptor-like 2 also known as CD312 is a protein encoded by the ADGRE2 gene. EMR2 is a member of the adhesion GPCR family. Adhesion GPCRs are characterized by an extended extracellular region often possessing N-terminal protein modules that is linked to a TM7 region via a domain known as the GPCR-Autoproteolysis INducing (GAIN) domain.

<span class="mw-page-title-main">RUNX1</span> Protein-coding gene in humans

Runt-related transcription factor 1 (RUNX1) also known as acute myeloid leukemia 1 protein (AML1) or core-binding factor subunit alpha-2 (CBFA2) is a protein that in humans is encoded by the RUNX1 gene.

<span class="mw-page-title-main">MN1 (gene)</span> Protein-coding gene in the species Homo sapiens

MN1 is a gene found on human chromosome 22, with gene map locus 22q12.3-qter. Its official full name is meningioma 1 because it is disrupted by a balanced translocation (4;22) in a meningioma.

<span class="mw-page-title-main">Wilms tumor protein</span> Transcription factor gene involved in the urogenital system

Wilms tumor protein (WT33) is a protein that in humans is encoded by the WT1 gene on chromosome 11p.

<span class="mw-page-title-main">HOXA9</span> Protein-coding gene in humans

Homeobox protein Hox-A9 is a protein that in humans is encoded by the HOXA9 gene.

<span class="mw-page-title-main">CBFB</span> Protein-coding gene in the species Homo sapiens

Core-binding factor subunit beta is a protein that in humans is encoded by the CBFB gene.

<span class="mw-page-title-main">CEBPA</span> Protein-coding gene in the species Homo sapiens

CCAAT/enhancer-binding protein alpha is a protein encoded by the CEBPA gene in humans. CCAAT/enhancer-binding protein alpha is a transcription factor involved in the differentiation of certain blood cells. For details on the CCAAT structural motif in gene enhancers and on CCAAT/Enhancer Binding Proteins see the specific page.

<span class="mw-page-title-main">KMT2A</span> Protein-coding gene in the species Homo sapiens

Histone-lysine N-methyltransferase 2A, also known as acute lymphoblastic leukemia 1 (ALL-1), myeloid/lymphoid or mixed-lineage leukemia1 (MLL1), or zinc finger protein HRX (HRX), is an enzyme that in humans is encoded by the KMT2A gene.

<span class="mw-page-title-main">Eukaryotic translation elongation factor 1 alpha 1</span> Constitutive promoter

Elongation factor 1-alpha 1 (eEF1a1) is a translation elongation protein, expressed across eukaryotes. In humans, it is encoded by the EEF1A1 gene.

<span class="mw-page-title-main">RUNX1T1</span> Protein-coding gene in humans

Protein CBFA2T1 is a protein that in humans is encoded by the RUNX1T1 gene.

<span class="mw-page-title-main">FIP1L1</span> Protein-coding gene in the species Homo sapiens

Factor interacting with PAPOLA and CPSF1 is a protein that in humans is encoded by the FIP1L1 gene. A medically important aspect of the FIP1L1 gene is its fusion with other genes to form fusion genes which cause clonal hypereosinophilia and leukemic diseases in humans.

<span class="mw-page-title-main">PHF6</span> Protein-coding gene in the species Homo sapiens

PHD finger protein 6 is a protein that in humans is encoded by the PHF6 gene.

<span class="mw-page-title-main">CFAP298</span> Gene of the species Homo sapiens

Cilia- and flagella-associated protein 298 is a protein encoded by CFAP298 gene. It is of interest in part for its association with various diseases. It has been found in high levels in the bone marrow of patients with a negative prognosis of acute myeloid leukemia and an abnormal karyotype. Male Alzheimer's patients have shown a decrease in expression of CFAP298 in their blood cells. The CFAP298 gene lies within the critical region of Down Syndrome. There are no clear paralogs in humans, but the gene has homologues widely conserved among animals, fungi, and algae.

<span class="mw-page-title-main">Musashi-2</span> Protein-coding gene in the species Homo sapiens

Musashi-2, also known as Musashi RNA binding protein 2, is a protein that in humans is encoded by the MSI2 gene. Like its homologue musashi-1 (MSI1), it is an RNA-binding protein involved in stemness.

Hematopoietic SH2 Domain Containing (HSH2D) protein is a protein encoded by the hematopoietic SH2 domain containing (HSH2D) gene.

CUX1 is an animal gene. The name stands for Cut like homeobox 1. The term "cut" derives from the "cut wing" phenotype observed in a mutant of Drosophila melanogaster. In mammals, a CCAAT-displacement activity was originally described in DNA binding assays. The human gene was identified following purification of the CCAAT-displacement protein (CDP) and has been successively been called CDP, Cut-like 1 (CUTL1), CDP/Cut and finally, CUX1.. Cut homeobox genes are present in all metazoans. In mammals, CUX1 is expressed ubiquitously in all tissues. A second gene, called CUX2, is expressed primarily in neuronal cells.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Tanner SM, Austin JL, Leone G, Rush LJ, Plass C, Heinonen K, et al. (November 2001). "BAALC, the human member of a novel mammalian neuroectoderm gene lineage, is implicated in hematopoiesis and acute leukemia". Proceedings of the National Academy of Sciences of the United States of America. 98 (24): 13901–6. Bibcode:2001PNAS...9813901T. doi: 10.1073/pnas.241525498 . PMC   61139 . PMID   11707601.
  2. "Tissue expression of BAALC - Summary - The Human Protein Atlas". www.proteinatlas.org. Retrieved 2017-11-15.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Wang X, Tian QB, Okano A, Sakagami H, Moon IS, Kondo H, Endo S, Suzuki T (February 2005). "BAALC 1-6-8 protein is targeted to postsynaptic lipid rafts by its N-terminal myristoylation and palmitoylation, and interacts with alpha, but not beta, subunit of Ca/calmodulin-dependent protein kinase II". Journal of Neurochemistry. 92 (3): 647–59. doi: 10.1111/j.1471-4159.2004.02902.x . PMID   15659234. S2CID   23562935.
  4. 1 2 3 4 5 Database, GeneCards Human Gene. "BAALC Gene - GeneCards | BAALC Protein | BAALC Antibody". www.genecards.org. Retrieved 2017-11-15.
  5. 1 2 3 "24997-1-AP". www.ptglab.com. Retrieved 2017-11-15.
  6. 1 2 Damm F, Heuser M, Morgan M, Wagner K, Görlich K, Grosshennig A, et al. (April 2011). "Integrative prognostic risk score in acute myeloid leukemia with normal karyotype". Blood. 117 (17): 4561–8. doi: 10.1182/blood-2010-08-303479 . PMID   21372155.
  7. 1 2 3 4 5 6 7 Xiao SJ, Shen JZ, Huang JL, Fu HY (July 2015). "Prognostic significance of the BAALC gene expression in adult patients with acute myeloid leukemia: A meta-analysis". Molecular and Clinical Oncology. 3 (4): 880–888. doi:10.3892/mco.2015.562. PMC   4486884 . PMID   26171200.
  8. 1 2 "Swiss-Model | Q8WXS3". swissmodel.expasy.org. Retrieved 2017-11-30.
  9. 1 2 3 4 5 Xu B, Chen G, Shi P, Guo X, Xiao P, Wang W, Zhou S (January 2012). "shRNA-Mediated BAALC knockdown affects proliferation and apoptosis in human acute myeloid leukemia cells". Hematology. 17 (1): 35–40. doi: 10.1179/102453312X13221316477499 . PMID   22549446. S2CID   23319837.
  10. 1 2 3 4 5 6 7 Heesch S, Schlee C, Neumann M, Stroux A, Kühnl A, Schwartz S, Haferlach T, Goekbuget N, Hoelzer D, Thiel E, Hofmann WK, Baldus CD (August 2010). "BAALC-associated gene expression profiles define IGFBP7 as a novel molecular marker in acute leukemia". Leukemia. 24 (8): 1429–36. doi: 10.1038/leu.2010.130 . PMID   20535151.
  11. Weber S, Haferlach T, Alpermann T, Perglerová K, Schnittger S, Haferlach C, Kern W (2016). "Feasibility of BAALC gene expression for detection of minimal residual disease and risk stratification in normal karyotype acute myeloid leukaemia". British Journal of Haematology. 175 (5): 904–916. doi: 10.1111/bjh.14343 . PMID   27662611. S2CID   10664675.
  12. Heuser M, Berg T, Kuchenbauer F, Lai CK, Park G, Fung S, et al. (March 2012). "Functional role of BAALC in leukemogenesis". Leukemia. 26 (3): 532–6. doi: 10.1038/leu.2011.228 . PMID   21869843.