REC8

Last updated
REC8
Identifiers
Aliases REC8 , HR21spB, REC8L1, Rec8p, REC8 meiotic recombination protein
External IDs OMIM: 608193; MGI: 1929645; HomoloGene: 3768; GeneCards: REC8; OMA:REC8 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001048205
NM_005132

NM_020002
NM_001360389
NM_001360390

RefSeq (protein)

NP_001041670
NP_005123

NP_064386
NP_001347318
NP_001347319

Location (UCSC) Chr 14: 24.17 – 24.18 Mb Chr 14: 55.86 – 55.86 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Meiotic recombination protein REC8 homolog is a protein that in humans is encoded by the REC8 gene. [5] [6] [7] [8]

Contents

Rec8 is a meiosis-specific component of the cohesin complex that binds sister chromatids in preparation for the two divisions of meiosis. Rec8 is sequentially removed from sister chromatids. It is removed from the arms of chromosomes in the first division - separating homologous chromosomes from each other. However, Rec8 is maintained at centromeres so that sister chromatids are kept joined until anaphase of meiosis II, at which point removal of remaining cohesin leads to the separation of sister chromatids.

Function

This gene encodes a member of the kleisin family of SMC (structural maintenance of chromosome) protein partners. The protein localizes to the axial elements of chromosomes during meiosis in both oocytes and spermatocytes. REC8 protein appears to participate with other cohesins STAG3, SMC1B and SMC3 in sister chromatid cohesion throughout the whole meiotic process in human oocytes. [9] In the mouse, the homologous protein is a key component of the meiotic cohesion complex, which regulates sister chromatid cohesion and recombination between homologous chromosomes. Multiple alternatively spliced variants, encoding the same protein, have been found for this gene. [8]

Rec8 remains in complex with SMC proteins until anaphase, where it is degraded by Separase once the spindle assembly checkpoint is bypassed. Unlike the other Kleisin family member, Scc1, Rec8 must be phosphorylated prior to degradation. Prior to anaphase, Rec8 is protected from phosphorylation by Protein Phosphatase 2 (PP2A-B56) in mouse. PP2A is recruited to cohesin by Shugoshin 2 (Sgo2; SGOL2 in yeast). Bypass of the spindle assembly checkpoint activates Separase, which then degrades phosphorylated Rec8 and untethers Cohesin from sister chromatids, allowing for segregation of chromosomes.

Interactions

REC8 has been shown to interact with SMC3. [7]

Related Research Articles

<span class="mw-page-title-main">Meiosis</span> Cell division producing haploid gametes

Meiosis is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one copy of each chromosome (haploid). Additionally, prior to the division, genetic material from the paternal and maternal copies of each chromosome is crossed over, creating new combinations of code on each chromosome. Later on, during fertilisation, the haploid cells produced by meiosis from a male and a female will fuse to create a zygote, a cell with two copies of each chromosome again.

<span class="mw-page-title-main">Nondisjunction</span> Failure to separate properly during cell division

Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division (mitosis/meiosis). There are three forms of nondisjunction: failure of a pair of homologous chromosomes to separate in meiosis I, failure of sister chromatids to separate during meiosis II, and failure of sister chromatids to separate during mitosis. Nondisjunction results in daughter cells with abnormal chromosome numbers (aneuploidy).

<span class="mw-page-title-main">Spindle checkpoint</span> Cell cycle checkpoint

The spindle checkpoint, also known as the metaphase-to-anaphase transition, the spindle assembly checkpoint (SAC), the metaphase checkpoint, or the mitotic checkpoint, is a cell cycle checkpoint during metaphase of mitosis or meiosis that prevents the separation of the duplicated chromosomes (anaphase) until each chromosome is properly attached to the spindle. To achieve proper segregation, the two kinetochores on the sister chromatids must be attached to opposite spindle poles. Only this pattern of attachment will ensure that each daughter cell receives one copy of the chromosome. The defining biochemical feature of this checkpoint is the stimulation of the anaphase-promoting complex by M-phase cyclin-CDK complexes, which in turn causes the proteolytic destruction of cyclins and proteins that hold the sister chromatids together.

<span class="mw-page-title-main">Synapsis</span> Biological phenomenon in meiosis

Synapsis or Syzygy is the pairing of two chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of meiosis. When homologous chromosomes synapse, their ends are first attached to the nuclear envelope. These end-membrane complexes then migrate, assisted by the extranuclear cytoskeleton, until matching ends have been paired. Then the intervening regions of the chromosome are brought together, and may be connected by a protein-DNA complex called the synaptonemal complex. During synapsis, autosomes are held together by the synaptonemal complex along their whole length, whereas for sex chromosomes, this only takes place at one end of each chromosome.

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

Separase, also known as separin, is a cysteine protease responsible for triggering anaphase by hydrolysing cohesin, which is the protein responsible for binding sister chromatids during the early stage of anaphase. In humans, separin is encoded by the ESPL1 gene.

SMC complexes represent a large family of ATPases that participate in many aspects of higher-order chromosome organization and dynamics. SMC stands for Structural Maintenance of Chromosomes.

<span class="mw-page-title-main">Cohesin</span> Protein complex that regulates the separation of sister chromatids during cell division

Cohesin is a protein complex that mediates sister chromatid cohesion, homologous recombination, and DNA looping. Cohesin is formed of SMC3, SMC1, SCC1 and SCC3. Cohesin holds sister chromatids together after DNA replication until anaphase when removal of cohesin leads to separation of sister chromatids. The complex forms a ring-like structure and it is believed that sister chromatids are held together by entrapment inside the cohesin ring. Cohesin is a member of the SMC family of protein complexes which includes Condensin, MukBEF and SMC-ScpAB.

<span class="mw-page-title-main">SMC1A</span> Protein-coding gene in humans

Structural maintenance of chromosomes protein 1A (SMC1A) is a protein that in humans is encoded by the SMC1A gene. SMC1A is a subunit of the cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. In somatic cells, cohesin is formed of SMC1A, SMC3, RAD21 and either SA1 or SA2 whereas in meiosis, cohesin is formed of SMC3, SMC1B, REC8 and SA3.

Chromosome segregation is the process in eukaryotes by which two sister chromatids formed as a consequence of DNA replication, or paired homologous chromosomes, separate from each other and migrate to opposite poles of the nucleus. This segregation process occurs during both mitosis and meiosis. Chromosome segregation also occurs in prokaryotes. However, in contrast to eukaryotic chromosome segregation, replication and segregation are not temporally separated. Instead segregation occurs progressively following replication.

<span class="mw-page-title-main">RAD21</span> Protein-coding gene in humans

Double-strand-break repair protein rad21 homolog is a protein that in humans is encoded by the RAD21 gene. RAD21, an essential gene, encodes a DNA double-strand break (DSB) repair protein that is evolutionarily conserved in all eukaryotes from budding yeast to humans. RAD21 protein is a structural component of the highly conserved cohesin complex consisting of RAD21, SMC1A, SMC3, and SCC3 [ STAG1 (SA1) and STAG2 (SA2) in multicellular organisms] proteins, involved in sister chromatid cohesion.

<span class="mw-page-title-main">SMC3</span> Protein-coding gene in humans

Structural maintenance of chromosomes protein 3 (SMC3) is a protein that in humans is encoded by the SMC3 gene. SMC3 is a subunit of the Cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. Cohesin is formed of SMC3, SMC1, RAD21 and either SA1 or SA2. In humans, SMC3 is present in all cohesin complexes whereas there are multiple paralogs for the other subunits.

<span class="mw-page-title-main">STAG2</span> Protein-coding gene in humans

Cohesin subunit SA-2 (SA2) is a protein that in humans is encoded by the STAG2 gene. SA2 is a subunit of the Cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. In somatic cells cohesin is formed of SMC3, SMC1, RAD21 and either SA1 or SA2 whereas in meiosis, cohesin is formed of SMC3, SMC1B, REC8 and SA3.

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

Wings apart-like protein homolog (WAPL) is a protein that in humans is encoded by the WAPAL gene. WAPL is a key regulator of the Cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. Cohesin is formed of SMC3, SMC1, RAD21 and either SA1 or SA2. Cohesin has a ring-like arrangement and it is thought that it associates with the chromosome by entrapping it whether as a loop of DNA, a single strand or a pair of sister chromosomes. WAPL forms a complex with PDS5A or PDS5B and releases cohesin from DNA by opening the interface between SMC3 and RAD21.

<span class="mw-page-title-main">SMC6</span> Protein-coding gene in the species Homo sapiens

Structural maintenance of chromosomes protein 6 is a protein that in humans is encoded by the SMC6 gene.

<span class="mw-page-title-main">PDS5B</span> Protein-coding gene in the species Homo sapiens

Sister chromatid cohesion protein PDS5 homolog B(PDS5B) is a protein that in humans is encoded by the PDS5B gene. It is a regulatory subunit of the Cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. The core cohesin complex is formed of SMC3, SMC1, RAD21 and either SA1 or SA2. PDS5 associates with WAPL to stimulate the release of cohesin from DNA but during DNA replication PDS5 promotes acetylation of SMC3 by ESCO1 and ESCO2.

<span class="mw-page-title-main">SMC5</span> Protein-coding gene in the species Homo sapiens

Structural maintenance of chromosomes protein 5 is a protein encoded by the SMC5 gene in human.

<span class="mw-page-title-main">STAG1</span> Protein-coding gene in the species Homo sapiens

Cohesin subunit SA-1 (SA1) is a protein that in humans is encoded by the STAG1 gene. SA1 is a subunit of the Cohesin complex which mediates sister chromatid cohesion, homologous recombination and DNA looping. In somatic cells cohesin is formed of SMC3, SMC1, RAD21 and either SA1 or SA2 whereas in meiosis, cohesin is formed of SMC3, SMC1B, REC8 and SA3. There is a nonprofit community formed for those with a STAG1 Gene mutation at www.stag1gene.org.

Sister chromatid cohesion refers to the process by which sister chromatids are paired and held together during certain phases of the cell cycle. Establishment of sister chromatid cohesion is the process by which chromatin-associated cohesin protein becomes competent to physically bind together the sister chromatids. In general, cohesion is established during S phase as DNA is replicated, and is lost when chromosomes segregate during mitosis and meiosis. Some studies have suggested that cohesion aids in aligning the kinetochores during mitosis by forcing the kinetochores to face opposite cell poles.

<span class="mw-page-title-main">SMC1B</span> Protein-coding gene in the species Homo sapiens

Structural maintenance of chromosomes protein 1B (SMC-1B) is a protein that in humans is encoded by the SMC1B gene. SMC proteins engage in chromosome organization and can be broken into 3 groups based on function which are cohesins, condensins, and DNA repair. SMC-1B belongs to a family of proteins required for chromatid cohesion and DNA recombination during meiosis and mitosis. SMC1B protein appears to participate with other cohesins REC8, STAG3 and SMC3 in sister-chromatid cohesion throughout the whole meiotic process in human oocytes.

<span class="mw-page-title-main">STAG3 (gene)</span> Protein-coding gene in the species Homo sapiens

Stromal antigen 3 is a protein that in humans is encoded by the STAG3 gene. STAG3 protein is a component of a cohesin complex that regulates the separation of sister chromatids specifically during meiosis. STAG3 appears to be paramount in sister-chromatid cohesion throughout the meiotic process in human oocytes and spermatocytes.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000100918 Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000002324 Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. Parisi S, McKay MJ, Molnar M, Thompson MA, van der Spek PJ, van Drunen-Schoenmaker E, Kanaar R, Lehmann E, Hoeijmakers JH, Kohli J (May 1999). "Rec8p, a meiotic recombination and sister chromatid cohesion phosphoprotein of the Rad21p family conserved from fission yeast to humans". Molecular and Cellular Biology. 19 (5): 3515–28. doi:10.1128/MCB.19.5.3515. PMC   84144 . PMID   10207075.
  6. Xu H, Beasley MD, Warren WD, van der Horst GT, McKay MJ (Jun 2005). "Absence of mouse REC8 cohesin promotes synapsis of sister chromatids in meiosis". Developmental Cell. 8 (6): 949–61. doi: 10.1016/j.devcel.2005.03.018 . PMID   15935783.
  7. 1 2 Lee J, Iwai T, Yokota T, Yamashita M (Jul 2003). "Temporally and spatially selective loss of Rec8 protein from meiotic chromosomes during mammalian meiosis". Journal of Cell Science. 116 (Pt 13): 2781–90. doi:10.1242/jcs.00495. PMID   12759374. S2CID   11040339.
  8. 1 2 "Entrez Gene: REC8L1 REC8-like 1 (yeast)".
  9. Garcia-Cruz R, Brieño MA, Roig I, Grossmann M, Velilla E, Pujol A, Cabero L, Pessarrodona A, Barbero JL, Garcia Caldés M (2010). "Dynamics of cohesin proteins REC8, STAG3, SMC1 beta and SMC3 are consistent with a role in sister chromatid cohesion during meiosis in human oocytes". Hum. Reprod. 25 (9): 2316–27. doi:10.1093/humrep/deq180. PMID   20634189.

Further reading