Skip to content
LabsTrail

Published

-Cyclin B mediated phosphorylation of PP2A-B56 on B56 Par1 .T73T75 controls mitotic entry timing and Schizosaccharomyces pombe cell size

Lenka Halova, Yvonne Connolly, Duncan Smith, Janni Petersen, Iain Hagan

doi:10.1098/rsob.260089

Abstract

Mitosis is triggered when the rising activity of CDK1-Cyclin B, amplified by the CDK1/Cdc25/Wee1 feedback loop, overcomes inhibitory signalling from Wee1 and counteracting phosphatases. CDK-opposing phosphatases PP1, PP2A-B55 and PP2A-B56 are regulators of mitosis. A screen for differentially phosphorylated sites in a ΔPP1 dis2 genetic background in Schizosaccharomyces pombe identified phosphorylation of T73 or T75 in the regulatory B56 Par1 subunit. The B56 Par1 .T73T75 phosphorylation is directly mediated by CDK1-Cyclin B, and a phospho-mimetic mutation increased while a non-phosphorylatable mutation reduced PP2A-B56 Par1 phosphatase activity. Blocking B56 Par1 .T73T75 phosphorylation reduced cell length in unperturbed divisions from 14 to 12 μm, without causing pleiotropic defects. Therefore, blocking phosphorylation at T73T75 alone prematurely unlocked amplification of the CDK1/Cdc25/Wee1 feedback loop, advancing cells into mitosis. Signalling from T73T75 reveals for the first time that timely mitotic commitment in unperturbed cycles is mediated by PP2A-B56.

This paper is a public record. Anyone with a DKG node can fetch it and check who submitted it: the panel shows how.

  1. Read
  2. Saved off-chain
  3. Minted on-chain
  4. Published

Verify it yourself

These values are public. You can check each one without trusting us.

The signature matches the submitter

The submission

Submitted by
0x9a17ec95e96f…c7bf9111
Submitter's signature
0x22c0479d66c7…a46f4d1c
Signed deadline (Unix seconds)
1792937580
Context graph
0xd701ed157232ad5e14bc…ain-prod

The asset

Minted to LabsTrail's node
0xd701ed157232…d86f13b3
Asset token (ERC-721, OriginTrail's DKGKnowledgeAssets)
97250665584536…42449963
Knowledge Asset (UAL)
did:dkg:base:84532/0xd…f13b3/43
PDF (CID)
bafybeiel5of2v…frb4defa
How to check this record
  1. Subscribe a DKG node to the context graph above and fetch the asset by its UAL: a UAL alone does not name its graph. The node returns the title, authors, PDF link, submitter, signature and deadline.
  2. Check the signature. It's EIP-712 typed data with the domain { name: "labstrail", version: "1", chainId: 84532 } and the type Submission(string cid,string contextGraph,uint256 deadline). A paper published before LabsTrail was renamed is signed with the name "verisci" instead. Any EIP-712 library recovers the signer to compare with the submitter; a smart-contract wallet is checked on chain with ERC-1271.
  3. Download the PDF by its CID. An IPFS client checks every block against its hash, so a changed file can't come back under this CID. To recompute the CID from a local copy, use Pinata's v1 import settings: CIDv1, raw leaves, 256 KiB chunks.
  4. Open the asset token on Basescan. It's an ERC-721 token in OriginTrail's DKGKnowledgeAssets contract, minted to LabsTrail's node, and its page shows when. The merkle root of the asset's statements is anchored with it, so any node can check that the content still matches.

Ratings

-Cyclin B mediated phosphorylation of PP2A-B56 on B56 Par1 .T73T75 controls mitotic entry timing and Schizosaccharomyces pombe cell size scores 80/100 for reproducibility readiness on LabsTrail. How the score works

Reproducibility readiness

How completely the paper reports what others need to repeat its work, from 0 to 100, checked against the reporting checklist for each kind of study in it. It doesn't say whether the findings are right.

80/ 100

The latest score on chain, from the rating requested 25 Oct 2026. Read the checks

A new rating adds its own score, and the latest one shows here. Free on testnet: you pay only gas. A wallet can have 3 ratings waiting at a time.

History

  1. 25 Oct 2026Scored 80Details
  1. Reproducibility readinesslive
  2. Human reviewnext
  3. Wet-lab replicationlater