Phosphatidylinositol-3-phosphatase SAC1 (SACM1L)

The protein contains 587 amino acids for an estimated molecular weight of 66967 Da.

 

Phosphoinositide phosphatase which catalyzes the hydrolysis of phosphatidylinositol 4-phosphate (PtdIns(4)P) (PubMed:24209621, PubMed:27044890, PubMed:29461204, PubMed:30659099). Can also catalyze the hydrolysis of phosphatidylinositol 3-phosphate (PtdIns(3)P) and has low activity towards phosphatidylinositol-3,5-bisphosphate (PtdIns(3,5)P2) (By similarity). Shows a very robust PtdIns(4)P phosphatase activity when it binds PtdIns(4)P in a 'cis' configuration in the cellular environment, with much less activity seen when it binds PtdIns(4)P in 'trans' configuration (PubMed:29461204, PubMed:24209621, PubMed:30659099). PtdIns(4)P phosphatase activity (when it binds PtdIns(4)P in 'trans' configuration) is enhanced in the presence of PLEKHA3 (PubMed:30659099). (updated: June 17, 2020)

Protein identification was indicated in the following studies:

  1. Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
  2. Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
  3. Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
  4. Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
  5. D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
  6. Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.

Methods

The following articles were analysed to gather the proteome content of erythrocytes.

The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.

PublicationIdentification 1Uniprot mapping 2Not mapped /
Obsolete
TrEMBLSwiss-Prot
Goodman (2013)2289 (gene list)227853205992269
Lange (2014)123412347281224
Hegedus (2015)2638262202352387
Wilson (2016)165815281702911068
d'Alessandro (2017)18261817201815
Bryk (2017)20902060101081942
Chu (2018)18531804553621387

1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry

The compilation of older studies can be retrieved from the Red Blood Cell Collection database.

The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.

No sequence conservation computed yet.

This protein is predicted to be membranous by TOPCONS.


Interpro domains
Total structural coverage: 83%
Model score: 33

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VariantDescription
dbSNP:rs1468542

The reference OMIM entry for this protein is 606569

Suppressor of actin mutations 1-like; sacm1l
Suppressor of actin 1; sac1
Kiaa0851

CLONING

By screening for cDNAs with the potential to encode large proteins expressed in brain, Nagase et al. (2000) identified a cDNA encoding SAC1, which they called KIAA0851, a 587-amino acid protein with 34% sequence identity with the yeast RSD1 (recessive suppressor of secretory defect) protein. RT-PCR detected expression of SAC1 in heart, brain, lung, liver, kidney, pancreas, testis, and ovary, and less abundant expression in skeletal muscle and spleen. Kiss et al. (2001) cloned mouse Sac1 which encodes a protein sharing 95% sequence identity with human SAC1. Both contain 2 transmembrane regions and a leucine zipper pattern. Both are predicted to be cytoplasmic proteins in the endoplasmic reticulum. Northern blot analysis in mouse showed high expression of a 4-kb transcript in brain, lung, liver, and kidney. A lower level of expression was seen in spleen and skeletal muscle, and no expression was observed in heart or testis.

GENE STRUCTURE

Kiss et al. (2001) determined that the SAC1 gene contains 20 exons and spans 55.7 kb. It has a large first intron of approximately 14 kb.

MAPPING

By sequence analysis, Kiss et al. (2001) mapped the SAC1 gene within a 250-kb putative tumor suppressor region on chromosome 3p21.3. ... More on the omim web site

Subscribe to this protein entry history

June 29, 2020: Protein entry updated
Automatic update: Entry updated from uniprot information.

Feb. 10, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.

Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated

Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated

Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated

June 20, 2017: Protein entry updated
Automatic update: comparative model was added.

March 16, 2016: Protein entry updated
Automatic update: OMIM entry 606569 was added.